Can a fetus in utero be declared sanctified to be sacrificed on the altar after it is born?
The Gemara on today’s daf raises this question and brings a disagreement between Bar Padda and Rabbi Yoḥanan. Bar Padda rules that a fetus cannot be sanctified, while Rabbi Yoḥanan believes that it can be sanctified. One explanation for their argument is that Bar Padda views this as a general rule of sanctified animals – only an animal that can be viewed as ready to be brought on the altar is considered a sanctified animal. According to Rav Yoḥanan, however, since the fetus can be sacrificed after it is born, that is sufficient to allow it to become sanctified even at an earlier stage.
One of the proofs that the Gemara brings in support of Rabbi Yoḥanan’s position teaches how someone can avoid his responsibility to give the firstborn animal to a kohen:
What device does one adopt in connection with a firstborn? If a pregnant animal was giving birth for the first time, one can say: ‘Whatever is in the inside of this animal shall become a burnt offering.’ If now the animal gives birth to a male it is a burnt offering.
Ultimately the Gemara suggests that Bar Padda can argue that this refers only to someone who consecrated the value of the fetus to the Temple, but not to someone who actually planned to sacrifice the fetus.
With regard to the sanctity of a bekhor – a firstborn animal – since such an animal only becomes sanctified once it is born from its mother’s womb (even if it is born of a Caesarian section it will not become sanctified), there is a possibility that the owner can arrange for the animal to avoid becoming classified with the holiness of a firstborn if he acts beforehand. In contemporary times, since there is no Temple and it would be impossible to sacrifice the bekhor, when an animal is pregnant with its first offspring it is recommended to prevent the animal from becoming sanctified, so the owner can even cause a blemish in the unborn fetus to prevent it from being born with the sanctity of a bekhor.