that this offspring born to the ewe that had not previously given birth is superior. The Gemara concludes: Consequently, it was necessary to teach each case.

MISHNA: With regard to an animal born by caesarean section and the offspring that follows it, since there is uncertainty whether each is a firstborn, neither is given to the priest. Rabbi Tarfon says: Both of them must graze until they become unfit, and they may be eaten in their blemished state by their owner. Rabbi Akiva says: Neither of them is firstborn; the first because it is not the one that opens the womb (see Exodus 13:12), as this animal did not itself open the womb, and the second because the other one preceded it.

GEMARA: The Gemara asks: With regard to what do Rabbi Akiva and Rabbi Tarfon disagree? Rabbi Tarfon is uncertain with regard to an animal that is a firstborn in one aspect, e.g., first to be born or first to open the womb, whether it is considered a firstborn or whether it is not considered a firstborn. And conversely, it is obvious to Rabbi Akiva that an animal which is a firstborn in only one aspect is not considered a firstborn.

With regard to the definition of a firstborn, the Sages taught in a baraita: This halakha can be derived by means of the form of exegesis known as: From a generalization that requires a detail, and from a detail that requires a generalization. How so? The verse states: “Sanctify to Me all the firstborn, that which opens any womb among the children of Israel, both of man and of animal, it is Mine” (Exodus 13:2). Had the verse written only the generalization: “Sanctify to Me all the firstborn,” one might have thought that even a female animal is included in the category of a firstborn. Therefore, the verse states the detail: “Every firstborn male…you shall sanctify to the Lord” (Deuteronomy 15:19).

And had the verse stated only: “Every firstborn male,” one might have thought that the first male offspring of an animal has firstborn status, even in a case where a female emerged from the womb before it. Therefore, the verse states: “That which opens any womb,” to teach that only an animal that itself opens its mother’s womb can be a firstborn. And had the verse stated only: “That which opens any womb,” one might have thought that even an animal that emerged from the womb after its older sibling was born by caesarean section is considered firstborn. Therefore, the verse states: “All the firstborn,” to teach that only the first offspring can be considered a firstborn.

The Gemara analyzes the baraita. Rav Sherevya said to Abaye: In the first clause, the baraita does not cite proof from the word “firstborn” that a male born after a female is not considered a firstborn. Apparently, an animal that is a firstborn in one aspect is called a firstborn, otherwise the baraita would not have had to derive the exclusion of a male born after a female from the phrase “that which opens any womb”; it could have cited the word “firstborn.” And in the last clause, the baraita does cite proof from the word “firstborn” that an animal whose older sibling was born by caesarean section is not considered a firstborn, despite the fact that it is a firstborn in one aspect. Apparently, a firstborn in one aspect is not called a firstborn. If so, the baraita is self-contradictory.

Abaye said to Rav Sherevya: Actually, a firstborn in one aspect is not called a firstborn, and this is what the first clause is saying: Had the verse stated only: “Every firstborn male,” one might have thought that even an animal born by caesarean section is itself considered a firstborn. Therefore, the verse states: “That which opens any womb,” to teach that an animal must itself open the womb to be considered a firstborn. The word “firstborn” cannot be cited as proof that an animal born by caesarean section is not a firstborn, as such an animal was in fact born first. Therefore, the tanna cites the phrase “that which opens any womb.” Once this phrase is cited, then a male born after a female is excluded as well, despite the fact that this halakha could have been derived from the word “firstborn.”

Ravina said that there is a different explanation: Actually, a firstborn in one aspect is called a firstborn, and the halakha is not derived from the meaning of the word “firstborn” itself, but from the fact that it is superfluous. And this is what the last clause is saying: If it enters your mind that an animal which emerged from the womb after its older sibling was born by caesarean section is sanctified, why do I need the word “firstborn” that the Merciful One wrote?