The Quantity Eaten to Obligate Bentching

(1) That is that He commanded us to bless Him after eating. And that is His saying, "And you shall eat and be satiated, and bless the Lord, your God" (Deuteronomy 8:10). And the language of the Tosefta (Tosefta Berakhot 6:1) is, "Grace over the meals is [an obligation] from the Torah, as it is stated, 'And you shall eat and be satiated, and bless.'" And the regulations of this commandment have already been explained in many places in Tractate Berakhot. (See Parashat Ekev, Mishneh Torah, Blessings 1.)

(1) It is a positive mitzvah from the Torah (as opposed to the other blessings, which were ordained by the Rabbis) to bless [God] after eating satisfying food, as [Deuteronomy 8:10] states: "When you have eaten and are satiated, you shall bless God, your Lord." The Torah itself requires a person to recite grace only when he eats to the point of satiation, (The Rabbis do not specify a standard quantity or measure of food that a person must eat to have reached this state. Rather, they leave the matter up to the person's own feelings.) as implied by the above verse, "When you have eaten and are satiated, you shall bless...." The Sages, however, ordained that one should recite grace after eating [an amount of bread equal] to the size of an olive. (equivalent to 28.8 grams according to Shiurei Torah, and 33 grams) according to the Chazon Ish.)

(1) One who eats less than an olives-worth, whether it's from bread or it's from other foods, or one drinks less than a quarter-log, whether it's from wine or other beverages, one blesses at the outset of blessing that is fit for that particular type and one does not bless a post-consumption blessing at all. And there are some who are unsure whether to say it's on something that it is like its creation, such as a crumb of grape or of a pomegranate that one blesses a post-consumption blessing even though there's not an olive’s-worth of it. Therefore, it is proper to be careful not to eat something less than an olive. And there are some who are further unclear with the post-consumption blessing over wine if one blesses upon it when one drinks only an olive’s-worth. Therefore, it is good to be careful not to drink less than an olive’s-worth or a quarter-log’s-worth.

(1) (1) Eating - All foods combine to form a kezayis for blessing them with a bracha achrona that is appropriate for them: if from the seven species, al hamichya is recited, if not from the seven species, borei nefashos is recited. If one ate half a kezayis from the seven species and another half a kezayis from something else, one recites borei nefashos. And this is the rule when eating half a kezayis of bread and half a kezayis of something that is blessed with borei nefashos, one recites the bracha achrona of borei nefashos. And all drinks combine to form a reviis. Eating and drinking (meaning eating less than a kezayis and drinking less than a reviis) does not combine even for the purpose of reciting borei nefashos. Broth made from vegetables combines to form a kezayis, for all food enhancers (a drink that comes to sweeten food) is food, and the same goes for bread soaked in a drink or wine or sauce. But if the bread was eaten with the sauce without dipping, it does not combine. However, if the sauce of the dish was made from things that are blessed like the dish (and is explained in Siman 205), it is possible that the sauce combines with the dish. and this needs further investigation (Chayei Adam). If someone eats a kezayis and takes a long time to eat it, if from the beginning of the meal until the end of the meal there is more than the time it takes to eat a half-loaf of bread, it is not combined. (And for the measurement of a half-loaf of bread, see later in Siman 212 that there are opinions whether it is 3 eggs or 4 eggs, and here it seems that even only for the time it takes to eat 3 eggs, the measurement of a kezayis, even for bread for the purpose of Birkas Hamazon, is only rabbinic and so it seems from the Chayei Adam). The Pri Megadim writes that this is only for the determining the measurement of a kezayis. But regarding the amount of bread for the purpose of satiety, which is an obligation from the Torah, one is obligated even if he ate a little, since in any case we read ‘and you shall be satiated’ in it. If there was a puffed bread (sufganim/doughnuts) that swelled until its air pockets were not felt, one who eats a kezayis of it as it is does not bless, because in truth he did not eat a kezayis. And also if there was a kezayis and it shrank and diminished in its size, we do not bless after it unless it expanded [Achronim]. Regarding drinking a reviis, if one drank and paused briefly and then drank again until he completed a reviis, there are those who say that it is not combined, and there are those who say that it is combined if he did not pause from the beginning of the drinking until the end of the drinking for more than the time it takes to eat a half-loaf [later in Siman 212, Seif 10]. And the Gra agreed there in his explanation that the law is like this second opinion. And behold, regarding drinking tea and coffee, which is usually drunk hot and difficult to drink without a break like other drinks, but (it is drunk) little by little. There is a great dispute among the poskim whether one needs to recite a bracha achrona for the first opinion mentioned above. The Machzis Hashekel and in Chayei Adam side with not reciting a bracha (achrona), and so it is written in Derech Hachaim and so is the universal custom. Practitioners (i.e. drinkers of tea or coffee) have the custom that at the end of their drinking, they leave a reviis’ worth to cool down a bit so that they can drink a reviis without interruption and recite a bracha achrona. It is good to do so in order to fulfill all opinions, especially according to the opinion of the Gra mentioned above, who ruled in favor of the second opinion that the measurement is the time it takes to eat a half-loaf for the purpose of combining even with drinking. It is certainly correct to do so. If one ate less than the required amount and went outside and immediately returned, he certainly needs to bless again initially, even with bread. It is necessary to examine if he returned and ate less than the required amount within the time it takes to eat a half-loaf if it is combined. Perhaps since he went outside it is considered as if his mind was distracted. And see in the Magen Avraham who argues that it is combined.

(1) And now I will explain the Gemara (Shabbat 21b): 'And those who are meticulous in the performance of the mitzvah (Mehadrin min HaMehadrin), Beit Shammai say: On the first day, one lights eight [candles], and from there on, decreases each day. And Beit Hillel say: On the first day, one lights one [candle], and from there on, increases each day.' And our sages of blessed memory said that the reason of Beit Shammai is [to correspond] to the bullocks of the festival [of Sukkot, which decrease in number each day]. And the reason of Beit Hillel is because 'we ascend in holiness and do not descend.'

It appears that they [Beit Shammai and Beit Hillel] are arguing based on a well-known principle: If a person lacks certain things they need, such as being hungry or thirsty or lacking clothing, then they have a longing to fulfill their desire and deficiency, and they feel distress because they lack what their soul yearns for. Additionally, they feel the physical distress of hunger and thirst. If bread and water come from a distant place, even though they have not yet eaten or drunk, they already feel joy because they know that there is something that will fulfill their deficiency. However, they are still hungry and thirsty. After they have eaten and drunk, they experience joy from being satisfied, and they praise Hashem for quenching their thirst.

All of this applies to a person who is lacking and does not know how to fulfill their lack, such as someone wandering in the desert, whose soul is parched, without bread, water, or clothing. They experience two types of distress: One, that their soul longs for the fulfillment of their lack, for food, drink, and clothing. When Hashem arranges for a person to come from afar and bring what is lacking—bread, water, and clothing—then as soon as they see that the things to fulfill their deficiency are before them, and they have 'bread in their basket,' they immediately feel joy because they see that they are able to satisfy their hunger and thirst. Although they have not yet eaten, drunk, or clothed themselves, they are immediately obligated to give thanks and praise to the Creator of heaven and earth who has provided sustenance for their soul and given them 'bread in their basket.' However, they still experience some distress from hunger and thirst.

But after they have eaten, drunk, and clothed themselves, they also experience pleasure because they are now satisfied, quenched, and of good heart, and they must bless the Creator, blessed be He, for the satisfaction, as it is written (Deuteronomy 8:10): 'And you shall eat, and be satisfied, and bless Hashem, your God...'

However, someone who is settled in their home with everything prepared before them, before they eat and drink, their heart only desires to eat and drink. After they have eaten and drunk, they are satisfied and bless Hashem. But for those who are traveling and lack everything, they have two longings, as explained above, and two kinds of joys: one for finding how to fulfill their lack, and one for the actual fulfillment of their deficiency.