As we learned on yesterday’s daf, there is a difference of opinion regarding the status of a viable fetus that was in utero at the time that its mother was slaughtered. Rabbi Meir rules that in such a case it would need its own sheḥita. The Ḥakhamim disagree, arguing that the mother’s slaughter permits the fetus.
What if the mother was a tereifa – an animal with a terminal condition that will not allow it to survive? The slaughter of a tereifa does not render the mother kosher, although it does affect the mother’s status with regard to laws of ritual purity (see above daf 73).
This question is discussed in the Gemara where we find Rabbi Ami teaching that if a person slaughtered a tereifa animal and found in it a viable fetus, then the positions are switched. Rabbi Meir who forbids the fetus (without slaughtering) permits this fetus, while the Ḥakhamim who permit the fetus without slaughtering would forbid this fetus, even if it is slaughtered on its own. Rabbi Ami’s argument is that Rabbi Meir views a viable fetus as an independent entity, so its mother’s slaughter has no impact on it. It cannot permit the fetus if it was a kosher slaughter and it cannot forbid the fetus if the mother’s slaughter was invalid. On the other hand, the Ḥakhamim who view the fetus as part of its mother and rule that the mother’s sheḥita affects the fetus will have to accept the fact that if the mother’s slaughter was invalid, we view it as if the fetus has been improperly slaughtered, and that cannot be rectified.
Rava argues with Rabbi Ami, saying that even according to the Ḥakhamim, the fetus can be permitted if it receives its own sheḥita, “for the Divine Law permits the fetus by the slaughtering of any two out of four simanim.” That is to say, although the mother’s slaughter did have some legal standing – it removes the ritual defilement of neveila – nevertheless the option remains for it to receive its own sheḥita, which will permit it entirely.