And the other ones, i.e., the Sages from the school of Rav, why don’t they derive the halakha that a firstborn is eaten for two days and one night from that verse? The Gemara answers that if it were derived from there, it would be possible to say that the verse is comparing the halakha of a firstborn to the breast and thigh of a thanks offering, which are eaten for only one day and night.

The Gemara asks: And the other one, Rav Yehuda, citing Rav, how does he respond to this? The verse states: “And their flesh shall be yours, as the breast of waving and as the right thigh, it shall be yours” (Numbers 18:18). The verse adds another mention of a form of the term being in the second phrase: “It shall be yours,” to teach that the priest has an additional day to eat a firstborn animal, i.e., that it is compared to the breast and thigh of a peace offering, not to that of a thanks offering.

The Gemara asks: And the other ones, the Sages from the school of Rav, how do they respond to this claim? The Gemara answers: With regard to the inference from there, it is possible to say that this phrase: “It shall be yours,” teaches with regard to a blemished firstborn that the owner must give it to the priest. This derivation is necessary, as we have not found this halakha that a blemished firstborn is given to a priest stated explicitly anywhere in the entire Torah.

The Gemara asks: And the other one, Rav Yehuda, citing Rav, from where does he derive that a blemished firstborn is given to a priest? The verse states: “And their flesh shall be yours,” in the plural, i.e., both an unblemished firstborn and a blemished firstborn. The Gemara asks: And the other ones, the Sages from the school of Rav, how do they respond? The Gemara answers that they would claim that the term “and their flesh” is written in the plural not because it is referring to blemished animals, but because it is said in reference to those firstborn animals of all the Israelites.

§ The mishna teaches: If a blemish developed within its first year, it is permitted for the owner to maintain the animal for the entire twelve months; if a blemish developed after twelve months have passed, it is permitted for the owner to maintain the animal for only thirty days. A dilemma was raised before the Sages: With regard to what case is the mishna speaking? Does the mishna mean that if a blemish developed within the animal’s first year, the owner is permitted to maintain the animal for the entire twelve months, and after the animal’s first year also for another thirty days? Or perhaps the mishna is referring to two different situations, i.e., in a case where the blemish developed within the animal’s first year the owner is permitted to maintain the animal for the entire twelve months, but nothing more; and in a case where it developed a blemish after one year, he is permitted to maintain it for only thirty days.

The Gemara suggests: Come and hear, as it is taught in a baraita: With regard to a firstborn in the present time, when there is no Temple and the animal cannot be brought as an offering, until it has developed a blemish that can be shown to an expert, it is permitted for the owner to maintain the animal for two or three years. But once the animal develops a blemish that can be shown to an expert, if the blemish developed within its first year, it is permitted for the owner to maintain it for the entire twelve months.

The baraita continues: After the animal’s first year, the owner does not have permission to maintain it even for one day, or even one hour. But due to the mitzva of returning a lost item to the owners, i.e., to give the owner time to find a priest and give him the animal, the Sages said: The owner is permitted to maintain the animal for thirty days. The Gemara assumes that in its latter clause the baraita is still addressing a blemish that developed in the first year. If so, the thirty days evidently apply in such a case.

The Gemara asks: But still, let the dilemma be raised with regard to that baraita itself: Are the thirty days granted in a case where the animal develops a blemish after its first year? Or perhaps these thirty days are granted if it develops a blemish before the end of its first year. In other words, when the baraita states: After its first year, this can be interpreted as referring to an animal whose blemish developed only then, or to one that had a blemish earlier and subsequently reached the end of its first year.

The Gemara suggests: Come and hear a baraita: If the animal developed a blemish on the fifteenth day within its first year, i.e., fifteen days before the end of its year, one completes for it fifteen days after its year. Conclude from this baraita that the owner may maintain a firstborn for an additional thirty days if it develops the blemish during its first year. The Gemara adds that this supports the opinion of Rabbi Elazar, as Rabbi Elazar says: With regard to an animal that developed a blemish toward the end of its year, one gives the owner thirty days from the time that the animal developed a blemish.

There are those who say that Rabbi Elazar says: From where is it derived with regard to a firstborn animal that developed a blemish during its first year that one gives the owner thirty days after its year? It is derived from a verse, as it is stated: “You shall eat it before the Lord your God year by year in the place that the Lord shall choose, you and your household” (Deuteronomy 15:20). It is derived from here that it may be eaten for one year and for another year. Which are the days that are considered to be a significant part of a year? You must say these are thirty days, which in certain respects are considered a complete year. This indicates that such a firstborn may be eaten for up to thirty days beyond the first twelve months.

According to this version of the discussion, the Gemara raises an objection: It is taught in a baraita that if the animal developed a blemish on the fifteenth day within its year, i.e., fifteen days before the end of its year, one completes for it fifteen days after its year. This indicates that with regard to completing a total of thirty days from the time the animal developed the blemish, yes, the owner may continue to maintain the animal in such a case. But if the blemish developed earlier, the baraita does not give him an extra thirty days beyond the conclusion of the year. The Gemara concludes: The refutation of the opinion of Rabbi Elazar is indeed a conclusive refutation.

MISHNA: In the case of one who slaughters the firstborn animal and only then shows its blemish to an expert to determine whether it is a blemish, and it was established by the expert that it is in fact a blemish that renders its slaughter permitted, Rabbi Yehuda deems it permitted for a priest to derive benefit from the firstborn. Rabbi Meir says: Since it was slaughtered not according to the ruling of an expert, it is prohibited. In a case involving one who is not an expert, and he examined the firstborn animal and it was slaughtered on the basis of his ruling, that animal must be buried, and the non-expert must pay compensation to the priest from his property.

GEMARA: Rabba bar bar Ḥana says: The dispute in the mishna between Rabbi Meir and Rabbi Yehuda does not apply in the case of a blemish on the cornea of the eye. In that situation everyone agrees that the animal is prohibited, because such blemishes in the eye change after the animal’s death, which means that there is no way of determining at that late stage whether it had been a permanent blemish or a temporary one. They disagree only with regard to blemishes that are on the animal’s body, which do not change after death. As Rabbi Meir holds that we issue a decree prohibiting the animal in the case of blemishes that are on the animal’s body due to the case of blemishes on the cornea, and Rabbi Yehuda holds that we do not issue a decree with regard to blemishes that are on the animal’s body due to the case of blemishes on the cornea.

This is also taught in a baraita: In the case of one who slaughters a firstborn animal and afterward shows its blemishes to an expert, Rabbi Yehuda says: If the blemish is on the cornea of the eye the animal is prohibited, because such blemishes change. But in the case of blemishes on its body the animal is permitted, because these blemishes do not change. Rabbi Meir says: Both this, blemishes on the eye, and that, blemishes on the body, are prohibited because they change. The Gemara inquires: Could it enter your mind that blemishes on the body are prohibited because they change? Do blemishes on the body change after the death of the animal? Rather, the blemishes on the body are prohibited due to a decree based on the case of blemishes on the cornea, which change.

Rav Naḥman bar Yitzḥak says: