הלכות שבת ט' הלכות צידה - סימן שטז

(1) With regard to any of the eight creeping animals mentioned in the Torah, one who traps them or wounds them on Shabbat is liable. The Torah states: “The following shall be impure for you among the creeping animals that swarm upon the earth: The weasel, and the mouse, and the dab lizard of every variety; and the gecko, and the land-crocodile, and the lizard, and the skink, and the chameleon” (Leviticus 11:29–30). With regard to other abominations and crawling things, one who wounds them is exempt. One who traps them for a specific need is liable; one who traps them for no specific need is exempt. With regard to animals or birds that are in his possession, i.e., an animal that is domesticated and under someone’s control, one who traps them is exempt; and, however, one who wounds them is liable.

(1) A person who plows even the slightest amount [of earth] is liable.1Since one can plant a seed in even the tiniest hole, even the smallest amount of plowing is considered significant (Shabbat 103a). One who weeds around the roots of trees, cuts off grasses, or prunes shoots to beautify the land2Our translation is based on the Rambam's Commentary on the Mishnah, Shabbat 12:2. Note Rashi and others, who offer different interpretations.
In his Commentary on the Mishnah (loc. cit.), the Rambam emphasizes that if one's intent when performing these activities is to gather the growths one is cutting, one is liable for reaping. If one's intent is to improve the tree so that it will grow better, one is liable for sowing, as stated in the following halachah. - these are derivatives of plowing. One is liable for performing even the slightest amount of these activities.
Similarly, one who levels the surface of a field - e.g., one who lowers a mound and flattens it or fills a vale - is liable for [performing a derivative of] plowing.3Note Shabbat 73b, which states that the Rambam's statements apply when these activities are performed outside. A person who performs these activities inside a house is liable for building. See Chapter 10, Halachah 12. [One is liable for performing] the slightest amount of these activities. Similarly, one who levels cavities [in the ground] to even the slightest degree is liable.

(2) A person who sows even the slightest amount is liable.4One is liable for sowing even the tiniest seed, since from it, a l arge plant can grow. A person who prunes a tree so that it grows performs an activity resembling sowing.5See Chapter 7, Halachah 3, and notes. In contrast, watering plants and trees on the Sabbath is considered merely a derivative of sowing.6Since watering does not involve a seed, plant, or tree itself (as do all of the activities mentioned in Chapter 7, Halachah 2), it is considered merely a derivative of sowing. One is liable for even the slightest amount. Similarly, one who soaks the seeds of wheat, barley, and the like in water [performs] a derivative of sowing7In one of his responsa, the Rambam explains that the source for his statements is Zevachim 94b, which mentions that one is liable for soaking seeds so they sprout. Others point to Shabbat 17b, which states that one is liable for soaking vetch, a type of bean fed to cattle. and is liable for even the slightest amount.

(3) One who reaps an amount the size of a dried fig is liable.8Reaping is important because it provides food for us to eat. Since an amount smaller than a dried fig is not considered a significant measure of food, one is not held liable for reaping until one reaps that amount. Plucking [fruit] is considered a derivative of reaping.9Plucking the fruit is considered merely as a derivative, because in contrast to reaping, which is done with a utensil, plucking is done by hand (Lechem Mishneh). Similarly, any person who removes produce from where it is growing is liable for reaping. Therefore, a person who removes grass growing from a rock, a parasite plant that grows on shrubs, or grasses that grow on a barrel is liable, for this is the place where they grow.10I.e., since these plants grow naturally in these places, one is held liable for removing them.
In contrast, a person who removes [fruit from a plant growing] in a flower pot that is not perforated is not liable, for this is not the [ordinary] place from which it grows.11Such plants grow naturally in the ground. By planting them in a flower pot, one separates them from their normal place of growth. Hence, they are no longer considered to be connected to their source, and according to the Torah there is no prohibition against picking fruit from such a plant. There is, however, a Rabbinic prohibition involved. (See Shulchan Aruch, Orach Chayim 336:7- 8.) If, however, the flower pot has a hole the size of a small root, [the plant] is considered as growing in the ground12It is able to receive nurture from the earth through the hole. (See Rashi, Shabbat 107b.) The above applies only in homes with earth floors where there is no interruption (except air) between the flower pot and the earth. See Shemirat Shabbat Kehilchasah, p. 326.
The difference between a flower pot that is perforated and one that is not perforated is relevant in many different contexts within Torah law. (See Hilchot Kilayim 1:2, 5:16; Hilchot Mechirah 3:16, and other sources.) and a person who picks fruit from it is liable.

(4) Whenever reaping from a plant causes it to grow larger - e.g., cattle-grass or beets - a person who harvests it without knowing of the prohibition involved is liable for two sin offerings: one because he [performed the labor of] reaping, and one because he [performed the labor of] planting.13Although the person performed merely one activity, since this activity produces effects that parallel those accomplished by two separate forbidden labors, he is liable to bring a sin offering for each. Similarly, a person who prunes [a tree] and desires to use [the branches he prunes] is liable for reaping and planting.
[The following rules apply to] a clod of earth on which grass is growing: If one lifted it from the earth and placed it on staves, one is liable for uprooting. If it was supported by staves and one placed it on the earth, one is liable for planting.14Significantly, Rashi (Shabbat 81b) and others maintain that one is not held liable in this instance. Although such activity is forbidden by Rabbinic decree, since the connection between the flower pot and the ground was never interrupted, one is not considered to have uprooted the plant (Shulchan Aruch HaRav 336:12).
When figs have dried out while on the tree, and similarly, [other] trees whose fruits have dried out - a person who picks them on the Sabbath is liable15Since they remain attached to the tree, they are governed by the same rules as other fruit.
Tosafot (Shabbat 150b) maintains that this ruling applies only when the stems attaching the fruit to the tree are still fresh. If they have also dried out, one is not held liable for picking the fruit. (See Be'ur Halachah 336.) although they are considered to be detached [from the tree] with regard to the laws of ritual purity.16See Hilchot Tum'at Ochalin 2:4-5.

(5) [The following rules apply to] one who uproots chicory or who prunes moist shoots:17Although the latter are most frequently used as fodder for animals, at times they are cooked and eaten by human beings. (See Sh'vi'it 7:5 and the Rambam's Commentary.) If he intends to use them as food [for human beings], the minimum measure [for which one is held liable for reaping] is the size of a dried fig.18As evident from the laws that follow, this is the minimum measure for which one is liable for all forbidden labors associated with food. Eating a lesser amount is not significant.
The Nodeh BiY'hudah (Orach Chayim, Vol. II, Responsum 34) notes that Shabbat 103a states that this measure applies when one gathers these substances in a field belonging to a colleague. When gathering in one's own field, by contrast, one is liable for even the slightest amount, since in doing so, one clears one's field, a derivative of the labor of plowing.
The Noda BiY'hudah explains that the Talmudic passage does not contradict the Rambam's decision. As mentioned in the previous halachot, one can be liable for transgressing two different forbidden labors when performing a single activity. Thus, as soon as one gathers any of these substances, one is liable for plowing. Should one one gather the amounts mentioned by the Rambam in this halachah, one is also liable for reaping. If he intends to use them as animal [fodder], the minimum measure is the amount necessary to fill the mouth of a young kid.19Based on Shabbat 76a, it appears that a mouthful of a kid is slightly less than the size of a dried fig. If he intends to use them for kindling, the minimum measure is the amount necessary to cook an egg.20This is the smallest amount of kindling wood that will be useful for a person.
[Similar measures apply with regard to the forbidden labor of] collecting food:21Although collecting food is a forbidden labor in its own right, the Rambam mentions it within the context of this halachah, because the measures for which one is held liable correspond exactly to those mentioned with regard to the previous law. If [one's intent is to use it] as [food for human beings], the minimum measure [for which one is held liable] is the size of a dried fig. [If one's intent is] for animal [fodder], the minimum measure is the amount necessary to fill the mouth of a young kid. [If one's intent is] for kindling, the minimum measure is the amount necessary to cook an egg.
Whenever the term "an egg" is used, the intent is an average-size chicken egg.22In contemporary measure, the size of an egg is determined as 57.6 cubic centimeters by Shiurei Torah and 100 cubic centimeters by Chazon Ish. Whenever the term "the amount necessary to cook an egg" is used, the intent is the amount necessary to cook a portion of an egg the size of a dried fig. A dried fig is one-third the size of an egg.23The Ra'avad states that this measure is not exact, and the actual amount is slightly larger. The difference between their opinions is based on the interpretation of Eruvin 80b and 82b. Similarly, their understanding of those passages affects their determination of many different significant measures in Torah law, for example, כדי אכילת פרס (the measure of time associated with the mitzvot and prohibitions connected with eating). The Shulchan Aruch (Orach Chayim 368:3) mentions both opinions.
[The forbidden labor of] collecting food applies only with regard to [collecting] the earth's produce.24Thus excluding salt or similar substances (Shabbat 73b). (Note the Kessef Mishneh's comments regarding the proper text of that Talmudic passage.) As the Rambam states in Chapter 21, Halachah 11, there is, however, a Rabbinic prohibition against gathering salt.
The Hagahot Maimoniot (21:8) state that just as sheaves are collected in a field - the place where produce grows - similarly, all activities that are derivatives of this forbidden labor must take place in or near the field or orchards in which the produce grows. The Tur (Orach Chayim 240) and others also accept this ruling. From Chapter 21, Halachah 11, it appears that the Rambam also follows this approach.

(6) A person who collects figs25Rav Moshe Kohen mentions that a person is liable only when he collects the fruit near the grooves of trees where they grow. Nevertheless, this opinion is not accepted outright by the later authorities. (See the Shulchan Aruch HaRav 340:15 and the Mishnah Berurah 340:38.) and makes a chain from them or one who pierces a hole through dates and passes a string through them until they are collected as a single entity performs a derivative26The commentaries have not cited a direct source for the laws stated in this halachah [although there is a parallel in the Jerusalem Talmud (Shabbat 7:2)]. Some cite this as an example of the Rambam's use of his own powers of deduction to determine derivatives for forbidden labors, so that every category of forbidden labor will be associated with derivatives. of the forbidden labor of collecting sheaves. The same applies in other similar circumstances.

(7) A person who threshes [an amount of grain the size of] a dried fig is liable. [The forbidden labor of] threshing applies only with regard to the earth's produce.27Rav Moshe Kohen questions this statement, for the derivatives of a forbidden labor must resemble the forbidden labor itself. Thus it is difficult to understand how the Rambam can make such a statement and also state that one is liable for extracting food or for milking an animal.
The Maggid Mishneh and the Rivash (Responsa 121) state that an animal that lives on the land (as opposed to fish and other creatures that live in the sea) can be considered as produce of the earth, because it derives its life from the earth's produce.
The Rambam's son, Rabbenu Avraham, however, does not accept the basic premise of the question and explains that a derivative of a forbidden labor can differ drastically from the forbidden labor itself. Accordingly, even though threshing applies only with regard to produce, its derivatives can involve animals (Birkat Avraham, Responsum 18).
Extracting produce from its shell28This applies to extracting kernels of grain from their husks or legumes from its pods. Nevertheless, the Eglei Tal allows one to remove the shells of onion and garlic, and Sh'vitat HaShabbat permits the removal of the hard shells of nuts. is a derivative of threshing; [a person who performs this activity] is liable. The same applies in all similar situations. Similarly, a person who milks an animal is liable for extracting food.29The Rambam's opinion is also accepted by Rashi (Shabbat 95a) and other authorities. Rabbenu Tam and other Rishonim agree that milking is forbidden according to Torah law, but consider it a derivative of other categories of labor. The Ramban (Shabbat 145) considers this merely a Rabbinic prohibition.
Note the Shulchan Aruch (Orach Chayim 305:20), which states that one may tell a gentile to milk an animal. This leniency is permitted because the animal will suffer pain if it is not milked. Other leniencies are also granted on the basis of the Rambam's statements in Halachah 10.
The question of milking animals attracted much attention in the early years of agricultural development in Eretz Yisrael, when the question arose regarding milking herds of animals when a gentile was not available. (See K'tzot HaShulchan, Vol. VI, p. 34 ff. and other sources.)
By the same token, a person who wounds an animal that has a hide30This concept is defined in Halachah 9.is liable for extracting,31Although it is universally accepted that one is liable for drawing blood from an animal, the Rishonim differ under which category of forbidden work this prohibition falls. Rashi, Shabbat 107a, mentions an opinion that extracting blood falls into the category of dyeing. Tosafot, Shabbat 75a, Ketubot 6b, offers a different interpretation, explaining that it is included in the category of slaughtering. provided he requires the blood32To use as a remedy or as food for a dog or other animal (Shabbat 106a; the Rambam's Commentary on the Mishnah, Shabbat 14:1).that flows from the wound. If, however, his intent is merely to wound [the animal], he is not liable, because his activity is destructive in nature.33See Chapter 1, Halachah 17. One is not liable unless one extracts a quantity of blood or milk equivalent to the size of a dried fig.34The Ra'avad objects to the Rambam's ruling, explaining that the minimum measures for liquids differ than those of foods. The Maggid Mishneh and the Kessef Mishneh support the Rambam's decision, explaining that since he considers these activities as derivatives of threshing, the minimum amount for which one is liable is the same as for threshing. It must be emphasized that according to the opinions of Rashi and Tosafot (see note 31), one is liable for extracting a quantity of blood smaller than the size of a dried fig.

(8) When does the above apply? When one wounds an animal, a wild beast, a fowl, or the like. If one wounds a fellow man, by contrast, one is liable although one's intent is to injure, for [this activity generates] pleasure.35This ruling depends on the Rambam's decision, Chapter 1, Halachah 7, where he states that one is liable for performing a מלאכה שאינה צריכה לגופה. Although the person is performing the forbidden labor for reasons very different from those that were involved in the construction of the Sanctuary, he is held liable because he is fulfilling his intent. It causes one's feelings to cool and one's anger to subside. Therefore, it is considered "constructive" in nature. Accordingly, even if one does not require the blood that one extracts, one is liable.36The Ra'avad objects to the Rambam's decision, based on his interpretation (which parallels that of Rashi) of Shabbat 105b. The Rambam, however, interprets this passage differently. (See the Maggid Mishneh.)

(9) The eight creeping animals mentioned in the Torah37Leviticus 11:29,30 mentions that the carcasses of these animals convey ritual impurity. There are various different opinions regarding the meanings of the Hebrew names for the species mentioned there. The Living Torah offers the following interpretation: the weasel, the mouse, the ferret, the hedgehog, the chameleon, the lizard, the snail, and the mole. have hides whose status is analogous to those of animals, beasts, and fowl with regard to the Sabbath laws.38The hides of these animals are tougher than the flesh beneath them. Therefore, there is a possibility that a wound will cause internal bleeding and that the blood will never be reabsorbed by the body. Other small creatures and crawling animals are not considered to have a hide [whose status is significant with regard to the Sabbath laws]. Therefore, one who wounds them is not liable.39The Rambam states that one is not liable for wounding other creeping animals even if one causes them to bleed. This decision is not accepted by most authorities (see Rashi and others, Chulin 46b), who maintain that one is not liable for causing these creatures to bleed internally. If, however, one causes external bleeding, one is liable.
The Shulchan Aruch (Orach Chayim 316:8) accepts the opinion of the other authorities. This decision depends on the difference of opinion mentioned in note 31 as to the category of forbidden labor of which causing bleeding is a derivative. As mentioned, the Rambam considers this activity a derivative of the labor of threshing, and threshing involves removing a substance from a hard shell. Since the hides of the other crawling animals are not tough, causing them to bleed cannot be considered a derivative of this labor. According to the opinion that bleeding is a derivative of slaughtering, however, one is liable for making any animal bleed, regardless of the nature of its hide (Ziv HaMishneh).
The question whether one may kill creeping animals that are dangerous is discussed in Chapter 10, Halachah 25 and notes.
One who wounds an animal, beast, fowl, or one of the above-mentioned eight creeping animals is liable whether he caused an open wound from which they bled or he made a bruise that caused internal bleeding.

(10) A person who squeezes fruit to extract its juice is liable for extracting. One is not liable until he extracts an amount of juice equivalent to the size of a dried fig. From the Torah itself, one is liable for pressing only grapes and olives.40Rashi, Shabbat 143b, explains that the reason is that the primary purpose which grapes and olives are grown is for these liquids. With regard to other fruits, by contrast, it is not as common to use them for juice. From his Commentary on the Mishnah (Shabbat 22:1), it appears that the Rambam also accepts this rationale.
(Rabbenu Nissim gives another reason: The juices of other fruits are not considered as liquids, but as food. See Hilchot Tum'at Ochalin 1:4. The Pri Megadim and others consider these as two separate rationales.)
Note Chapter 21, Halachah 12, which states that there is a Rabbinic prohibition against squeezing other fruits that are frequently used for juice (Shabbat 144b gives as examples, berries and pomegranates). If, however, it is not common to use a fruit for juice, there is no prohibition at all against squeezing juice from it. Note also the discussion in the Beit Yosef (Orach Chayim 320) regarding squeezing lemons to make lemonade.
It is, [however,] permitted to squeeze a cluster of grapes directly into food, since a liquid that is absorbed into food is considered as food. Thus, one is considered to be extracting food from food.41Rabbenu Chanan'el does not accept this leniency and maintains that one is liable. In a responsum, Rabbenu Asher states that a person who observes this stringency will be blessed (Beit Yosef, Orach Chayim 320). Nevertheless, if one squeezes these liquids into a vessel that does not contain food,42It is prohibited to do this even if one ultimately intends to mix these beverages into food. Note, however, Shulchan Aruch Harav 320:6, which states that since one ultimately intends to mix the liquid into food, the prohibition is merely Rabbinic in nature. this is considered pressing and one is liable.
[Similarly,] one who milks directly into food43The Maggid Mishneh maintains that this law applies only on a festival, but not on the Sabbath. Since the animal may not be slaughtered on the Sabbath, it is not considered as "food." Similarly, the Shulchan Aruch (Orach Chayim 505) quotes this law with regard to the laws of festivals and not with regard to the Sabbath laws. or one who sucks with his mouth is not liable.44See Chapter 21, Halachah 14. Based on this leniency, there are authorities who allow one to suck the juice from grapes and other fruits. Other authorities forbid this. (See Ramah, Orach Chayim 320:1.) One is liable only when one milks into a container.45The Shulchan Aruch HaRav 320:21 states that a person who milks an animal and lets the milk flow from the animal to the ground is not liable, for this is not the normal manner in which an animal is milked. This can be interpreted as the implication of the Rambam's words: "One is liable only when one milks into a container."

(11) A person who winnows or separates [an amount of food the size of] a dried fig is liable.46With regard to separation, this can also be interpreted as separating the unwanted matter (whether more or less than the size of a dried fig) to produce an amount of food the size of a dried fig (Minchat Chinuch). The Yeshu'ot Ya'akov 319:1 differs and maintains that both the food and the unwanted matter are counted when reckoning the amount equal to the dried fig. Causing milk to curdle is a derivative [of the category] of separating.
Similarly, a person who separates the dregs from liquids is liable for having performed a derivative of separating or a derivative of sifting.47See Halachah 14 and also Chapter 21, Halachah 17, for more particulars regarding the separation of dregs from liquids. [The particular category of forbidden labor is not defined,] because the labors of winnowing, separating, and sifting resemble each other.48See the Eglei Tal, who questions whether these three activities can be combined. Thus, if one winnowed an amount of grain one third the size of a dried fig, and one separated and sifted the same amount, is one liable for a sin offering under such circumstances or not? [If so,] why were they reckoned as three [separate categories? Because every labor that was performed in the Sanctuary is counted as a separate category.

(12) A person who separates food from unwanted matter49Primarily, the forbidden labor of separating involves separating unwanted matter from food. In the Sanctuary, it involved separating unwanted matter - pebbles and the like - from the herbs used for the dyes. Nevertheless, if one uses a utensil that is made for the purpose of separation, one is liable even when separating food from unwanted matter.
See also the Turei Zahav 319:12 who states that the prohibition against separation applies, not only to the separation of unwanted matter from food, but also to the separation of unwanted matter from substances other than food. This opinion is accepted by the later authorities. and one who separates one type of food from another food50In this instance, since one does not wish to partake of the other food, it is considered unwanted matter, and it is forbidden to separate the food one desires from it. When, however, one separates one portion of one type of food from another portion of the same food, one is never considered to be separating (Shulchan Aruch HaRav 319:4-5; Mishnah Berurah 319:15). using a sifter or a strainer is liable. If one separates using a tray51Our translation is taken from the Rambam's Commentary on the Mishnah, Keilim 16:3. Rashi translates this as a sieve. His interpretation is accepted by most authorities. or a pot with compartments,52Our translation is taken from the Rambam's Commentary on the Mishnah, loc. cit:1. one is not liable. It is permitted to separate food by hand to eat immediately.53The Ramah (Orach Chayim 319:1) explains that "immediately" means "for the purpose of the meal that one is attending." If one separates the food for use at a later time, one is liable, as stated in the following halachah.

(13) A person who separates unwanted matter from food is liable,54As mentioned in the notes on the previous halachah, this is the primary form of the labor of separating. even if he does so using only one hand.55The word "one" is not found in the authoritative Yemenite manuscripts. It is, however, included in the quotation of this halachah in the Shulchan Aruch (Orach Chayim 319:4). The Mishnah Berurah 319:17 notes that some texts of the Shulchan Aruch also do not include it.
According to those versions that do include it, the intent is that using only one hand is not considered an abnormal way of performing this labor. A person who separates turmos beans from their shucks is liable, for the shucks sweeten them when they are cooked together. Therefore, one is considered to be taking unwanted matter from food and is held liable.56As explained in the notes on Chapter 3, Halachah 12, the turmos beans are very bitter and must be cooked seven times before they are edible. The shucks help absorb some of this bitterness. Hence, they are not considered as unwanted matter. (See Rashi, Shabbat 74a.)
A person who separates food from unwanted matter by hand and sets it aside [to serve] at a later time,57One is not held liable for separating food in the process of eating, for the Torah's intent was surely not to prevent a person from eating in the normal manner. Separating food and setting it aside to be used later is not necessary to allow one to eat normally. Hence, it is considered in the category of this forbidden labor (Shulchan Aruch HaRav 1-2). even later on [the Sabbath] itself, is considered to have separated for the purpose of storage and is held liable.
If there were two types of food mixed together before a person, he may separate one from the other and place it aside to eat immediately. If he separated [one from the other] and set it aside [to serve] at a later time, even later on [the Sabbath] itself, he is liable - for example, one separated food in the morning to eat in the late afternoon.58The Rambam's intent should not be misinterpreted: even if one decides to eat the food set aside at a second meal served earlier in the day, one is also held liable. It was merely common custom to eat two meals during the daytime on the Sabbath - one in the morning and one in the evening. (See Magen Avraham 319:6.)

(14) A person who filters the dregs from wine, oil, water, or other liquids, using a utensil appropriate for this purpose59The Rambam's words literally mean "their filter." The Shulchan Aruch 319:10 states "filter," seemingly implying all filters, even one not specifically made for that liquid. is liable,60See Halachah 11. provided he removes the dregs from an amount of liquid equivalent to the size of a dried fig. One may, however, filter wine61One must, however, do so in a manner slightly different from the way one filters these liquids during the week, as the Rambam states in Chapter 21, Halachah 17. that has no dregs, or clear water, with a handkerchief or with an Egyptian basket62A basket made of woven palm branches. so they will become crystal clear.63The Rashba and other authorities differ with the Rambam, based on their interpretation of Shabbat 139b. According to the Rashba, one may filter even cloudy wine with a handkerchief or other strainer of this nature, since this is not the normal manner in which this activity is performed.
According to the Rambam, although one would not be liable for straining the wine in this manner, it would still be forbidden by Rabbinic decree. The only filtering that is permitted is filtering wine that is already fit to be drunk, so that it will become crystal clear. One might ask: Of what value is such an act? The answer is that precisely because most people would not consider this activity of value, and only the most spoiled individuals would require it, is it permitted. (According to the Rashba, such beverages may even be filtered with an ordinary filter.) Though the Shulchan Aruch (Orach Chayim 319:10) mentions the Rambam's view, the Rashba's ruling is favored.
We may pour water over wine dregs64The dregs were placed in a strainer on Friday, and one desires to pour the water over them on the Sabbath day (Rav Ovadiah of Bertinoro, Shabbat 20:2). so they will become clear.65To remove any residue of wine that might be left in the dregs (ibid.). [Similarly,] we may place a raw egg in a mustard strainer so that it becomes clear.66The intent is to mix the egg with mustard lying at the bottom of the strainer that has already been strained before the Sabbath (Shabbat 134a). In his Commentary on the Mishnah (Shabbat 20:2), the Rambam states that when raw eggs are mixed with coarse foods, they cause the lighter matter to rise above the heavier, coarse matter. Thus, by mixing the egg with the mustard, one will cause it to undergo a further process of refinement. Nevertheless, this is not included in the forbidden labor of separating.
It must be noted that the Tur (Orach Chayim 319) explains that the problem in question in this instance is that the egg yolk will pass through the strainer, while the albumen will not. Nevertheless, this is not considered a derivative of the forbidden labor of separating. The Shulchan Aruch (Orach Chayim 319:15) follows this interpretation.
When one has mixed mustard on Friday, one may stir it by hand or with a utensil to make it fit to drink [on the Sabbath].67Since the mustard is already strained and is fit to be used, there is no difficulty in stirring it further. (See also Chapter 22, Halachah 12.) Similarly, while wine is in the process of fermentation, one may pour out a barrel of wine together with the dregs over handkerchiefs, for the dregs have not been finely separated from the wine and they are still considered a single mixture.68Rashi, Shabbat 139b, explains that this straining process will not be very effective. Hence, it is permitted. Shulchan Aruch HaRav 319:14 focuses on the Rambam's words and explains that since the wine and the dregs are considered a single mixture, the forbidden labor of separation does not apply. The concept of separation applies when the desired entity and the dregs are distinct, and this is not true until the wine has completed the fermentation process. The same applies to mustard and all similar substances.69I.e., although it is forbidden to strain mustard using a strainer on the Sabbath, one may strain it through a handkerchief (Or Sameach).

(15) A person who grinds [an amount of grain the size of] a dried fig is liable. One who crushes spices or herbs in a mortar is performing the labor of grinding and is held liable.70Indeed, in the construction of the Sanctuary, it was herbs that were crushed for use as dyes.
A person who cuts a vegetable that has been detached from its source [into small pieces] performs a derivative of the labor of grinding.71See Chapter 7, Halachah 5, Chapter 21, Halachah 18. In those halachot, the Rambam adds the expression "to cook it," implying that one is not liable for cutting vegetables one intends to eat raw. When the Shulchan Aruch (Orach Chayim 321:12) quotes this law, it omits the above term, leading to the conclusion that one is liable even for cutting vegetables that one desires to eat raw. For this reason, in his gloss the Ramah clarifies that one is liable only when one cuts the vegetables and then stores them for later use, if one partakes of them immediately, one is not liable.
Similarly, a person who saws wood in order to benefit from the sawdust, and similarly, one who files a piece of metal is liable72See Chapter 7, Halachah 5.for filing even the slightest amount.73Because any amount of the dust he desires will be useful for him. This is evident from Chapter 18, Halachah 5. A person who chops wood is not liable [for grinding] until he produces enough chips to cook an amount of egg the size of a dried fig.74Since he intends to use the wood for kindling, he must have enough wood to perform an an activity of at least minimal importance. (See Chapter 18, Halachah 4.)

(16) A person who sifts [an amount of flour the size of] a dried fig is liable.75The Rambam does not mention derivatives for this category of forbidden labor, because, as mentioned in Halachah 11, sifting resembles the categories of separating and winnowing, and it is not clear which of these categories of forbidden labor the derivatives of these activities fall under.
A person who kneads [dough76This addition follows the opinion of the Minchat Chinuch. The Eglei Tal differs, maintaining that for a person to be liable, the flour used for the dough must be this size before water is added. the size of] a dried fig is liable. Mixing earth [for use as cement] is a derivative of kneading. What is the minimum amount for which one is liable? The amount necessary to make a crucible for a goldsmith.77This measure is derived from Chapter 18, Halachah 11. The activity of mixing cement cannot be performed with ash, coarse sand, bran, or the like.78The forbidden labor of kneading involves adding water to a collection of granular substances - e.g., flour or cement - and mixing them until they cling together as a single mass. Since the substances mentioned in this clause of the halachah do not adhere to each other, one can never be held liable for performing this forbidden labor with them. As mentioned in the notes to Chapter 21, Halachot 33-34, this opinion is not accepted by all authorities.
There is another difference of opinion among the Sages and later Rabbis pertinent to this matter. Rabbi Yosse bar Yehudah (Shabbat 155b) mentions that kneading involves actually mixing the dough with one's hands. Rabbi Yehudah HaNasi differs and maintains that one is liable for kneading as soon as one pours water into flour. This opinion is accepted by some authorities (Sefer HaTerumot) and is referred to in the Shulchan Aruch (Orach Chayim 321:16).
A person who places sesame seeds, flax seeds, or the like in water is liable for kneading,79As mentioned in Halachah 2, if a person places seeds into water so they sprout, he is liable for performing a derivative of sowing. (See Mishnah Berurah 336:51 which states that this applies only when one has the intent that they sprout. A person who soaks seeds so that they soften is not liable.) If one pours water over the seeds mentioned in this halachah, one is liable for kneading. because they become attached to each other.