MISHNA: When a pregnant kosher animal is slaughtered, the slaughter also renders the consumption of its fetus permitted. Even if an animal was encountering difficulty giving birth and meanwhile the fetus extended its foreleg outside the mother animal’s womb and then brought it back inside, and then the mother animal was slaughtered, the consumption of the fetus is permitted by virtue of the slaughter of the mother animal. But if the fetus extended its head outside the womb, even if it then brought it back inside, the halakhic status of that fetus is like that of a newborn, and the slaughter of the mother animal does not permit the consumption of the fetus. Rather, it requires its own slaughter.

If, prior to slaughtering an animal, one severs pieces from a fetus that is in the womb and leaves those pieces in the womb, their consumption is permitted by virtue of the slaughter of the mother animal. By contrast, if one severs pieces of the spleen or of the kidneys of an animal and then slaughters it, then even if those pieces are left inside the animal their consumption is prohibited, because an organ severed from a living being is not permitted by the subsequent slaughter of the animal. This is the principle: An item that is part of an animal’s body that was severed prior to its slaughter is prohibited even after slaughter, and an item that is not part of its body, i.e., its fetus, is permitted by virtue of its slaughter.

GEMARA: The Gemara qualifies the first ruling of the mishna: Rav Yehuda says that Rav says: But as for the limb itself, i.e., the foreleg, its consumption is prohibited, even though the fetus brought it back inside prior to the slaughter.

What is the reason for this? It is as the verse states: ''And flesh, in the field, a tereifa, you shall not eat'' (Exodus 22:30). A tereifa is an animal with a wound that will cause it to die within twelve months; its consumption is prohibited even if it is ritually slaughtered. The Gemara interprets the verse as teaching a principle: Once flesh whose permitted status is dependent on being within a certain area, e.g., sacrificial meat within the Temple courtyard, has gone outside of its boundary, i.e., the area in which it is permitted, which the verse describes as being ''in the field,'' it becomes permanently prohibited, like a tereifa. Likewise, the permitted status of a fetus is dependent on its being within the womb when the mother animal is slaughtered. Accordingly, if any part of the fetus leaves the womb before the slaughter, it is rendered permanently prohibited.

The Gemara raises a difficulty: We learned in the mishna: If an animal was encountering difficulty giving birth and as a result the fetus extended its foreleg outside the mother animal’s body but then brought it back, and then the animal was slaughtered, the consumption of the fetus is permitted by virtue of the slaughter of the mother animal. The Gemara assumes: What, is the mishna not referring to the entire fetus, including the limb, i.e., the foreleg, when it states that its consumption is permitted by the slaughter? This would contradict Rav’s ruling. The Gemara answers: No, the mishna is referring to the rest of the fetus, apart from the foreleg.

The Gemara asks: If the mishna is referring to the rest of the fetus, why state specifically that the fetus brought back its foreleg? Even if it did not bring it back the rest of the fetus would still be permitted. The Gemara answers: The same is true, that the rest of the fetus is permitted, even if it did not bring back its foreleg. But since the tanna of the mishna wants to teach in the latter clause: If the fetus extended its head, even though it brought it back, the halakhic status of that fetus is like that of a newborn and is permitted only through its own slaughter, therefore he also taught in the first clause that the fetus brought back its foreleg, for stylistic reasons, despite the fact that the ruling is not limited to that case.

The Gemara asks: And concerning this latter clause itself, what does it teach us? Does it teach that once the fetus extended its head, that is considered a birth? But we have already learned this in a mishna (Bekhorot 46a): Who is considered a firstborn with regard to inheritance but is not considered a firstborn with regard to the requirement to be redeemed by giving five shekels to the priests? It is a son who came after the miscarriage of an underdeveloped fetus. The mishna adds that the category of stillbirth includes the case of a child who did not reach full term, even if its head emerged alive, or a fully developed, nine-month-old fetus whose head emerged dead.

The Gemara infers from the final clause of the mishna: The reason a son born following the miscarriage is considered a firstborn with regard to inheritance is that the head of the miscarriage emerged only after it was already dead. But if its head had initially emerged alive, even if it then died before being fully delivered, the son born after him would not be considered a firstborn even with regard to inheritance. Apparently, this is because the emergence of the head alive is considered a birth, and therefore any subsequent child cannot be considered the firstborn. Evidently, it is unnecessary for the mishna here to teach this definition of a birth.

And if you would say that the mishna there teaches us the definition of birth with regard to a person, and the mishna here teaches us that the same definition applies to an animal, another problem remains, as the Gemara will presently explain.

Before explaining the problem with this suggestion, the Gemara explains why it is necessary to teach the definition with regard to both people and animals: Because the definition of birth with regard to a person cannot be derived from that of an animal, as an animal does not have a concealed opening [prozdor] to the womb, unlike women, whose thighs conceal the opening to their womb. Consequently, even if the definition were stated with regard to an animal, one might limit it to animals, as that stage is immediately visible; whereas in women it is not. And conversely, the definition of birth with regard to an animal cannot be derived from that of a person, as the form of a person’s face is significant because people are created in the image of God, and their faces bear the mark of their intelligence, which is not true of animals. Consequently, perhaps the emergence of the head alone is considered a birth only with regard to a person.

The Gemara proceeds to explain why the above suggestion is not a solution: With regard to this halakha also, that the emergence of the head of an animal is considered a birth, we have already learned it in a mishna (77a): If part of a placenta emerged from the womb of an animal before it was slaughtered, its consumption is prohibited even after the mother animal is slaughtered. The reason for this is just as the placenta is an indication of the presence of a fetus in a woman, so too, it is an indication of the presence of a fetus in an animal. Consequently, it is possible that the part of the placenta that emerged contained the head of the fetus, and accordingly it would be considered to have been born. The slaughter of the mother animal would therefore not permit it for consumption. Evidently, it is unnecessary for the mishna here to teach the definition of a birth even with regard to an animal.

The Gemara has established that the latter clause does not teach any novelty. Accordingly, it returns to challenging Rav’s ruling: Granted, the mishna is understood if you say that the statement that the fetus brought its foreleg back inside the mother animal, which is mentioned in the first clause of the mishna, is written specifically in order to teach the novelty that the foreleg is permitted if it was brought back before the slaughter, in contrast to Rav’s ruling. If so, then one can claim the mishna taught it in the latter clause due to the first clause, so that they would be parallel stylistically, and no novelty is necessary in the latter clause.

But if you say the first clause is not written specifically and does not teach a novelty, but rather the mishna is referring to the permitted status of the rest of the fetus, which is permitted even if it does not bring back its foreleg, and you also say the latter clause is not written specifically to teach a novelty, since the definition of birth is already taught in a mishna elsewhere, then why does it need to teach the halakha that the foreleg or head were brought back at all? Perforce, the first clause must be referring to the permitted status of the foreleg and limiting it specifically to the case where it was brought back inside. This contradicts Rav’s ruling.

The Gemara responds: No; actually, the mishna is referring to the permitted status of the rest of the fetus, but nevertheless, the statement that the fetus brought back its foreleg does teach a novelty. This is similar to that which Rav Naḥman bar Yitzḥak said, in explanation of a ruling in a baraita cited below, that it is necessary only with regard to the location of a cut limb on the fetus’s body. If the foreleg were to be severed at precisely the point that lay on the boundary between the inside and the outside of the womb, then the location of the cut on the fetus’s body would also be prohibited. Here too, one can explain that the ruling is necessary only with regard to the location of the cut, and it teaches that if the fetus did not bring back its foreleg, then not only is the foreleg prohibited but the location of the cut is also prohibited.

The Gemara suggests: Come and hear a challenge to Rav’s ruling from a baraita: If an animal was encountering difficulty giving birth, and as a result the fetus extended its foreleg outside the mother animal’s body and then brought it back inside and then afterward one slaughtered its mother, its consumption is permitted by virtue of the slaughter of the mother animal. But if one first slaughtered its mother, and only afterward did the fetus return its foreleg back inside, its consumption is prohibited.

If the fetus extended its foreleg outside and one cut it off, and then afterward one slaughtered its mother, then the part of the foreleg that was outside and was cut off is ritually impure and its consumption is prohibited, as it has the status of a limb cut from a living animal, which is forbidden. And the rest of the fetus that was inside is ritually pure and its consumption is permitted by virtue the slaughter of the mother animal.

If one slaughtered its mother and only afterward cut off the foreleg that had been extended outside,