All the measures in the Torah connected to eating are the volume of an olive-bulk, except for the amount of food that renders objects impure, because the verse changed its expression in this case, and the Sages altered the measure accordingly. The proof of this, that the Sages gave it a different measure because the verse used different language for it, is from Yom Kippur. Also in the case of Yom Kippur the Sages assigned a different measure because the verse used a different phrase. The Gemara asks: How did the Sages learn that the verse changed its expression? They learned from: “Any soul which shall not be afflicted” (Leviticus 23:29). The verse does not state: Any soul that shall eat, but rather: “Any soul which shall not be afflicted.” How did the Sages change its measure? One does not violate the prohibition unless he has eaten the volume of a large date-bulk, as opposed to the usual olive-bulk.

The Gemara asks: And what does the baraita mean when it says: A proof for this is from Yom Kippur? Why is the verse pertaining to ritual impurity not sufficient to show that the Sages changed the measure based on the different words in the verse? The Gemara answers: If we learned it only from there, the case of impurity, I would have said that that is the style of the verse, and no halakha can be derived from it. Therefore, the verse pertaining to Yom Kippur teaches that whenever a verse deviates from the usual language, it implies a change in the halakha as well.

§ The Gemara asks: From where do we derive that the measure for impure foods is the volume of an egg-bulk? Rabbi Abbahu said that Rabbi Elazar said that the verse states: “Of all food [okhel] which may be eaten [ye’akhel], on which water comes shall be ritually impure” (Leviticus 11:34). The double usage of the root akhal teaches that the ritual impurity of food applies even to the amount which can be described as food that comes on account of food, i.e., food that comes from another food. And which food is that? A chicken egg. The Gemara asks: And say it is referring to a kid, which comes from a mother goat, and is therefore also food that comes from another food. The Gemara answers: It lacks ritual slaughter. The young goat is not yet food, since it is not edible until it has been slaughtered. The Gemara asks further: And say it is referring to a ben pekua. Since the slaughter of its mother made it fit to eat, the fetus itself need not be slaughtered, even if it survives and continues to live independently of its mother. The Gemara answers: The calf still requires cutting, since it cannot be eaten live, but it does not require ritual slaughter.

The Gemara asks: Even if we claim that the measure for impure foods is an egg-bulk, one could say it is referring to the giant egg-bulk of the bird called bar yokhani. The Gemara answers: If you grasped many, you did not grasp anything; if you grasped few, you grasped something. This means that in a case of doubt, take the smaller number, as it is included in the larger number. Therefore, the correct measure is the volume of a chicken egg. The Gemara questions this: If so, say it is referring to a very small bird’s egg. Consequently, no proof can be brought from the verse that the volume of a chicken egg is the measure for ritual impurity.

Rabbi Abbahu himself said: The verse states: “Of all food which may be eaten.” This is referring to food that you can eat at one time. The Sages estimated: The esophagus cannot hold more than the volume of a chicken’s egg, and therefore this is the measure used for the ritual impurity of foods.

Incidental to the discussion on Torah measures, Rabbi Elazar said: One who unwittingly eats forbidden fat even today must write down the exact measure that he ate, lest another court come in the future and increase the measure.

The Gemara asks: What does it mean to increase the measure? If we say that a future court will obligate him to bring an offering even for the bulk of a small olive, which is less than what is considered an olive-bulk today, he would not be liable to bring a guilt-offering. Wasn’t it taught in a baraita: It was said with regard to guilt-offerings: “And if any one of the common people sin through error, in doing any of the things which the Lord has commanded not to be done, and be guilty” (Leviticus 4:27)? This teaches that one who repents due to his awareness, i.e., one who repents following becoming aware that he performed a transgression, brings an offering for his unwitting transgression.

However, one who does not repent due to his awareness that he sinned does not bring an offering for his unwitting action. Similarly, if one eats less than an olive-bulk, based on the current measures, he will not be obligated to bring a guilt-offering in the future if the measures change, even if the amount that he ate equals the volume of a revised olive-bulk. This is because the individual would not be bringing his offering because he became aware he had sinned, but because the Torah measures had been changed.

Rather, it should be explained as follows: It is possible that in the future a court will not obligate one to bring an offering until he has eaten the bulk of a large olive, which is more than today’s amount. One should write down how much he ate, since in the future a court might rule that the amount he ate is less than the size of an olive, and therefore he will not be obligated to bring an offering.

The Gemara returns to its first suggestion: According to what entered his mind initially, that in the future a court might obligate him to bring an offering for the bulk of a small olive, what is the meaning of increase the measure? Rabbi Elazar should have said decrease the measure. The Gemara answers: The statement may have meant that perhaps there will be an increase in offerings that are brought due to the smaller measure for liability.

With regard to this topic, Rabbi Yoḥanan said: Measures and punishments are halakha transmitted to Moses from Sinai. The Gemara expresses surprise at this: The punishments for all transgressions are written explicitly in the Torah, and therefore are not part of an oral transmission from Moses. Rather, this is what was said: Rabbi Yoḥanan said: Measures that determine liability for punishments are halakha transmitted to Moses from Sinai.

The Gemara comments: This was also taught in a baraita: Measures of punishments are halakha transmitted to Moses from Sinai. Others say: These measures were instituted by the court of Jabez. The Gemara questions this: How can this be? Isn’t it written: “These are the mitzvot which the Lord commanded Moses for the children of Israel at Mount Sinai” (Leviticus 27:34). The word “these” underscores that a prophet is not permitted to introduce any new element related to the Torah and its mitzvot from here on. Rather, over the course of time, the people forgot the measures; subsequently the prophets reestablished the measures and taught them to the masses.

§ We learned in the mishna that one who drinks a cheekful on Yom Kippur is liable. Rabbi Yehuda said that Shmuel said: This does not mean two cheeks actually full. Rather, the measure that determines liability is the volume of liquid if one pushes the drink to one side of his mouth, and it appears as though his cheek were full. The Gemara questions this: Didn’t we learn in the mishna: A cheekful, in the plural form, meaning two cheeks full? The Gemara answers: Say: Like two cheeks full in appearance. If viewed from only one side, one whose cheek is full appears as if his entire mouth is full.

The Gemara raises an objection to this from a baraita: How much does one need to drink on Yom Kippur to be liable? Beit Shammai say: A quarter-log, and Beit Hillel say: Two cheeks full. Rabbi Yehuda says in the name of Rabbi Eliezer: Like two cheeks full in appearance from the side, i.e. a single cheekful. Rabbi Yehuda ben Beteira says: The amount that one can swallow in one gulp. In this baraita, Beit Hillel’s opinion is that the measure for drinking on Yom Kippur is a cheekful. This implies that a cheekful means an actual cheekful.

The Gemara expresses surprise: Is the baraita preferable to the mishna? Since it was established that the measure in the mishna is so that it appears like a cheekful, so too, the baraita can be explained as meaning an amount that looks like two cheeks full. The Gemara questions further: If so, Beit Hillel require an amount that appears like two cheeks full; this is identical with the opinion of Rabbi Eliezer, who says: Like two cheeks full. The Gemara answers: We could say that the practical difference between them is evident in the case of a paltry cheekful, which is not a complete mouthful but slightly less. According to Beit Hillel, one is not liable unless he drinks a full cheekful; but according to Rabbi Eliezer, one is liable even for a paltry mouthful.

Rav Hoshaya strongly objects to this understanding: If so, if Beit Hillel’s measure is a single cheekful, then this is an instance of Beit Shammai’s leniencies and Beit Hillel’s stringencies, since the measure of a quarter-log is larger than a single cheekful. If so, why isn’t this debate listed in tractate Eduyyot, which lists all the cases where Beit Shammai are more lenient than Beit Hillel? He said to him: