this is what Rabban Shimon ben Gamliel said to him: Even until ten generations, the offspring are exempt. But according to Rav Huna, who says that the first tanna did not descend to any generational levels, what is the meaning of the phrase: Even until ten generations? The Gemara responds: Rav Huna could have said to you that the statement of Rabban Shimon ben Gamliel is referring to the second case of the mishna, where the Jew established the offspring in place of the mothers, as in that case the first tanna also descends to generational levels.

The Gemara comments: Come and hear an objection to the opinion of Rav Yehuda from the mishna: With regard to one who accepts animals as part of a guaranteed investment from a gentile, the direct offspring are exempt, and the offspring of the direct offspring are not exempt. This is apparently a conclusive refutation of the opinion of Rav Yehuda, who said that the offspring of the direct offspring are also exempt. The Gemara explains that Rav Yehuda could have said to you: I will say that the mishna means that they, the direct offspring, and their offspring are exempt. When the mishna said: The offspring are exempt, it was referring not to the offspring of the original animals given to the Jew, but to the offspring of those offspring.

The Gemara notes that there are those who say that there is a different version of this exchange: The mishna is actually written as: They, the direct offspring, and their offspring are exempt, which is apparently a conclusive refutation of the opinion of Rav Huna. The Gemara explains that Rav Huna could have said to you: One can say that the mishna means that they, i.e., the original animals given to the Jew, and their offspring are exempt. But the offspring of their direct offspring are obligated.

§ The mishna teaches: A ewe that gave birth to a goat of sorts and a goat that gave birth to a ewe of sorts are not subject to the obligation of a firstborn. Rav Oshaya came from Neharde’a and brought a baraita in his hand: With regard to an animal that has the appearance of a ewe and that was born to a goat, or a goat that was born to a ewe, Rabbi Meir deems it obligated, and the Rabbis deem it exempt.

Rav Hoshaya said to Rabba: When you go before Rav Huna, ask him: With regard to what does Rabbi Meir deem it obligated? If we say that it is with regard to the mitzva of a firstborn, that is difficult: But doesn’t Rabbi Meir agree that the verse: “But the firstborn of an ox” (Numbers 18:17), teaches that an animal is included in the mitzva of a firstborn only if it is an ox and its firstborn is an ox? In other words, the mitzva of the firstborn applies only if the offspring has the appearance of its mother.

Rather, Rabbi Meir’s ruling was with regard to the obligation of giving the first shearing of wool to the priest. The Gemara asks: But if so, doesn’t Rabbi Meir agree with that which the school of Rabbi Yishmael taught: Lambs whose fleece is tough are exempt from, i.e., not subject to giving, the first shearing of wool to the priest, as it is stated: “And if he were not warmed with the fleece of my sheep” (Job 31:20)? It is derived from this verse that only a fleece which is fit to warm a person, i.e., fleece that is soft, is classified as wool that must be given to the priest. Since the fleece of the goat-like offspring of a ewe is tough, it should be excluded from the mitzva of the first shearing.

Rabba said to Rav Hoshaya: Let us see; what are we dealing with here? We are dealing with a ewe that gave birth to a goat of sorts and its father was a goat. And they disagree as to whether or not one needs to be concerned with the offspring’s paternity in terms of the matter of the prohibition against slaughtering itself and its offspring on the same day. As Rabbi Meir holds that one needs to be concerned with its paternity, and therefore one is liable for slaughtering the male goat and its goat-like offspring in a single day, and the Rabbis hold that one need not be concerned with its paternity.

The Gemara objects: But if that is so, then let us say that they disagree on whether or not one needs to be concerned with the offspring’s paternity in general, i.e., with regard to the prohibition against slaughtering an animal and its offspring on the same day, which is the subject of the dispute of Ḥananya and the Rabbis (see Ḥullin 78b). Instead of citing a dispute in the unusual case of a ewe that gave birth to a goat of sorts, the baraita should have simply stated that Rabbi Meir agrees with the opinion of Ḥananya that the prohibition against slaughtering an animal and its offspring applies even to a father and its offspring.

Rather, Rabbi Meir’s ruling is actually with regard to the obligation of a firstborn, and here we are dealing with a ewe born to a ewe born to a goat, which means that the offspring is similar in appearance to its mother, but not to its grandmother. One Sage, Rabbi Meir, holds: Follow the appearance of an offspring’s mother to determine whether or not the mitzva of a firstborn applies, and as this offspring has the appearance of its mother, it does not have the status of an animal that resembles a different species. Accordingly, the mitzva of firstborn applies.

And one Sage, the Rabbis, holds: Follow the appearance of the mother of its mother to determine whether or not the mitzva of firstborn applies, and as this offspring does not have the appearance of its mother’s mother, it does have the status of an animal that resembles a different species. Consequently, the mitzva of firstborn does not apply.

And if you wish, say instead that we are dealing with a ewe born to a goat born to a ewe. One Sage, Rabbi Meir, holds: Its ovine nature was restored to its original state. That is, since the offspring resembles its older progenitor, the mitzva of firstborn applies. And one Sage, the Rabbis, holds: Its ovine nature was not restored to its original state, and in any case where the offspring is not like its mother, it is exempt from the mitzva of firstborn.

The Gemara cites another interpretation of the baraita. Rav Ashi says: The baraita is referring to a case where the offspring has some of the characteristics of its mother, and the opinion of Rabbi Meir is that of the mishna here, which rules that the mitzva of firstborn applies to an offspring that has some of its mother’s characteristics. And who are the Rabbis who disagree with Rabbi Meir? It is Rabbi Shimon, who says: The offspring does not have firstborn status unless its head and the majority of its body are similar to the appearance of its mother.

According to the second explanation of the baraita, Rabbi Meir maintains that a ewe born to a goat born to a ewe is counted a firstborn despite the fact that it does not resemble its mother. Rabbi Yoḥanan says: Nevertheless, Rabbi Meir concedes with regard to the goat of the New Moon offering that we require the son of a female goat. What is the reason? With regard to the New Moon offering the verse states: “And one male goat for a sin offering unto the Lord” (Numbers 28:15). The superfluous word “one” teaches that the offering must be particularly a goat, as it has been since the six days of Creation.

The Gemara asks: But is this derived from here? Isn’t it derived from there: “When a bull, or a sheep, or a goat, is brought forth” (Leviticus 22:27), as the phrase “a bull, or a sheep” serves to exclude diverse kinds, i.e., an animal born from two different species of animals, while the phrase “or a goat” serves to exclude an animal that resembles a different species?

The Gemara answers that both verses are necessary, as, had the halakha been derived only from there, the verse in Leviticus, I would say: That statement applies only where the resemblance to another species does not trace back to earlier generations, i.e., the animal does not resemble any of its progenitors, but in a case where it does trace back, I would say: No, the animal is fit for sacrifice. Therefore, it is derived from the verse in Numbers that the animal must be as it has been since the six days of Creation. And had it been derived only from here, the verse in Numbers, I would say: That statement applies only with regard to an obligatory offering, which is the subject of that verse, but in the case of a gift offering, the animal does not need to resemble its mother. Therefore, both verses are necessary.

The Gemara cites a series of statements discussing an animal that resembles another species. Rabbi Aḥa bar Yaakov says: Everyone concedes that one is not flogged due to the prohibition of diverse kinds for wearing its wool together with linen, as it is stated: “You shall not wear diverse kinds, wool and linen together” (Deuteronomy 22:11). Just as linen is a material that has not changed, so too, one is liable only for wearing wool from an animal that has not changed, i.e., an animal whose appearance does not differ from that of its progenitors.

Rav Pappa similarly says: Everyone concedes that the wool of an animal that resembles another species is unfit to be used as the sky-blue wool of ritual fringes, as it is stated: “You shall not wear diverse kinds…you shall make yourself twisted cords” (Deuteronomy 22:11–12). Just as linen is a material that has not changed, so too, only wool from an animal that has not changed may be used as the sky-blue wool.

Rav Naḥman bar Yitzḥak likewise says: Everyone concedes that its wool does not become ritually impure with leprous marks, as it is stated: “And when the mark of leprosy is in a garment, whether it be a woolen garment, or a linen garment” (Leviticus 13:47). Just as the linen of a garment has not changed, so too, only a garment made of wool from an animal that has not changed can become impure with leprous marks.

Rav Ashi says: Along these lines, we can say also that if one trellised a grapevine over a fig tree, its wine is unfit to be used for libations. What is the reason? The verse states: “An offering, and libations” (Leviticus 23:37). Just as an offering must be an animal that has not changed, so too, libations must come from wine produced by vines that were not changed.

Ravina objects to this suggestion: By that reasoning, if one trellised flax over a shrub, it should also be considered a changed product. But if so, you cannot say what Rabbi Aḥa bar Yaakov said in his earlier statement: Just as linen is a material that has not changed, as linen also changes according to Rav Ashi’s reasoning. Rav Ashi said to Ravina: With regard to this wine, its scent has changed, but with regard to that flax, its scent has not changed, and therefore its alteration is considered inconsequential.

MISHNA: In the case of a ewe that had not previously given birth, and it gave birth to two males and both their heads emerged as one, Rabbi Yosei HaGelili says: Both of them are given to the priest, as it is stated in the plural: “Every firstborn that you have of animals, the males shall be to the Lord” (Exodus 13:12). And the Rabbis say: It is impossible for two events to coincide precisely, i.e., their births were not at precisely the same time. Rather, one preceded the other, and therefore one of the males is given to the owner and one to the priest.

Rabbi Tarfon says: The priest chooses the better of the two. Rabbi Akiva says: They assess the value of the lambs between them and the priest takes the leaner of the two, as will be explained in the Gemara. And with regard to the second lamb that remains in the possession of the owner, since he may not partake of it due to its uncertain status as a firstborn, it must graze until it becomes blemished, at which point he may slaughter and eat it.