As we learned on yesterday’s daf (=page), 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 Me’ir rules that in such a case it would need its own shehitah. The Hakhamim disagree, arguing that the mother’s slaughter permits the fetus.
What if the mother was a terefah – an animal with a terminal condition that will not allow it to survive? The slaughter of aterefah 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 Ammi teaching that if a person slaughtered a terefahanimal and found in it a viable fetus, then the positions are switched. Rabbi Me’ir who forbids the fetus (without slaughtering) permits this fetus, while the Hakhamim who permit the fetus without slaughtering would forbid this fetus, even if it is slaughtered on its own. Rabbi Ammi’s argument is that Rabbi Me’ir 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 Hakhamim who view the fetus as part of its mother and rule that the mother’s shehitah 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 Ammi, saying that even according to the Hakhamim, the fetus can be permitted if it receives its own shehitah, “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 neveilah – nevertheless the option remains for it to receive its own shehitah, which will permit it entirely.