Using an object whose primary function is for a prohibited use, for the purpose of utilizing the object itself to perform a permitted action, is permitted.
Abaye raised an objection to the opinion of Rabba from the Tosefta: A mortar, if it still has garlic in it, one may move it on Shabbat, and if not, one may not move it. Apparently, under no circumstances may a mortar be used, even for an action that is generally permitted on Shabbat, because the mortar’s primary function is prohibited.
Rabba said to him: In accordance with whose opinion is this baraita? It is the opinion of Rabbi Neḥemya, who says: A vessel may not be moved on Shabbat except for the purpose of its designated use.
Abaye raised another objection to Rabba’s opinion. We learned in a mishna that Beit Shammai say: One may not take a large pestle from a mortar, which is typically used for a prohibited action, in order to cut meat on it for the purpose of a Festival. And Beit Hillel permit doing so due to the mitzva of rejoicing on the Festival. And everyone agrees that if one cut meat on it for the purpose of the Festival, that it is then prohibited to move it because there is no further need for it on the Festival. Apparently, it is prohibited to use an object whose primary function is for a prohibited use, even to perform a permitted action.
Initially, Rabba thought to respond to Abaye’s objection by saying that this mishna, too, is in accordance with the opinion of Rabbi Neḥemya, that a vessel may only be moved on Shabbat for the purpose of its designated use. However, he changed his mind once he heard that which Rav Ḥinana bar Shelemya said in the name of Rav: Everyone agrees in the case of launderers’ pins, presses, and clothing rods (Arukh), that since one is particular about them to ensure that they remain intact, he designates a place for them and does not move them for other purposes. Therefore, everyone agrees that it is prohibited to move them. Here, too, the mortar and pestle are specifically designated for a particular use and one designates a place for them; therefore, it is prohibited to move them.
It was stated that there was another amoraic dispute on this topic. Rabbi Ḥiyya bar Abba said that Rabbi Yoḥanan said: It was with regard to the hammer of goldsmiths that we learned it may be used to crack nuts. Although the goldsmith is particular about ensuring that the hammer remains smooth and avoids using it for any purpose other than its particular use, nevertheless, it was allowed to be used for other permitted actions. Rav Shemen bar Abba said: It was with regard to the hammer of spice merchants that we learned it may be used to crack nuts.
The Gemara explains: The one who said it is permitted to crack nuts on Shabbat using the hammer of spice merchants, all the more so that it is permitted to use a hammer typically used by goldsmiths. However, the one who said that it is only permitted to use a hammer used by goldsmiths, but with regard to the hammer of spice merchants, the merchant is particular about it and would not allow it to be used for cracking nuts. Use for other purposes would cause the hammer to absorb foreign smells, which would ruin the spices.
And we learned in the mishna: one may move a reed or a shuttle [karkar] in order to stick it into food. The Sages taught in a baraita: With regard to an unripe fig that one buried in straw to accelerate its ripening, and likewise with regard to a cake that one buried in coals in order to heat it, if part of it is exposed, it is permitted to move it on Shabbat. And if not, and it was completely covered, it is prohibited to move it lest one come to carry straw or coals, which are set-aside, along with it. It is prohibited for one to move set-aside objects or to cause them to be moved.
Rabbi Elazar ben Tadai says: One may insert a reed or a shuttle into an unripe fig or a cake that is buried in coals to remove it from its place, and the straw and the coals are shaken off on their own. Rav Naḥman says: The halakha is in accordance with the opinion of Rabbi Elazar ben Tadai.
The Gemara asks: Is that to say that Rav Naḥman holds: Moving an object in an atypical manner is not considered to be a bona fide act of moving and is permitted on Shabbat? Didn’t Rav Naḥman say: This radish that was buried in the dirt to protect it, if it was inserted from the top to bottom, i.e., the wider part of the radish is closer to the surface and the narrower part is farther, it is permitted to remove it from the dirt. If it was inserted from bottom to top, and the wider part was farther from the surface, it is prohibited because he thereby moves the dirt. Apparently, Rav Naḥman prohibits moving set-aside items even if one does so in an atypical manner. The Gemara answers: Rav Naḥman reversed his opinion with regard to that halakha of the radish.
We learned in the mishna: One is permitted to take an ordinary hand needle used for sewing clothes to extract a thorn with it. Rava, son of Rabba, sent the following question to Rav Yosef: Let our teacher teach us: With regard to a needle whose eye or point was removed, what is its legal status, i.e., is moving it on Shabbat permitted?
Rav Yosef said to him: You already learned the answer to that question in the mishna: One is permitted to take an ordinary hand needle used for sewing clothes to extract a thorn with it. And what does the thorn that is stuck in his flesh care whether the needle has an eye or whether it does not have an eye? Since the needle is suited for that purpose, it is permitted to move it.
Rava, son of Rabba, raised an objection to Rav Yosef from that which we learned in a mishna: A ritually impure needle whose eye or point was removed becomes ritually pure, because its status as a vessel is negated. Since it is no longer considered a vessel, why would it be permitted to move it?
Abaye said: Are you raising a contradiction from the halakhot of ritual impurity to the halakhot of Shabbat? With regard to ritual impurity, we require a functional utensil for it to become ritually impure or to retain impurity, and anything which is not functional is ritually pure. However, with regard to Shabbat we require something that is fit for use, and this too is fit to extract a thorn with it, and therefore, its legal status is that of a utensil and moving it is permitted.
Rava said: The one who raises the objection, raises the objection well. From the fact that with regard to ritual impurity it is not considered a utensil, with regard to Shabbat, it is also not considered a utensil, and if it is not a utensil it may not be moved on Shabbat.
The Gemara raises an objection to the opinion of Rava based on what was taught in a baraita: A needle, whether it is perforated or whether it is not perforated, it is permitted to move it on Shabbat. And they said that the status of a perforated needle is different only with regard to ritual impurity alone.
Abaye interpreted it according to the opinion of Rava: In this mishna, we are dealing with unfinished needles. Sometimes one decides to render them a utensil for other purposes without perforating them. However, in a case where its eye or its point was removed from the finished needle, its status as a vessel was negated, since a person throws it among the junk [gerutaot].
With regard to the matter of aligning the limbs of an infant on Shabbat when it is necessary to do so, Rav Naḥman prohibits doing so on Shabbat, due to concern that it is similar to the prohibited labor of completing the production process of a vessel, and Rav Sheshet permits doing so. Rav Naḥman says: From where do I say that this is the halakha? As we learned in a mishna: One may not make