Towards the end of Parashat Bo (13:13), we read God’s command to Benei Yisrael after the Exodus to redeem their firstborn sons. As the nation’s firstborns were spared from the plague that killed the firstborn children of Egypt on the night of the Exodus, firstborns must be treated as “sacred” and thus redeemed. We fulfill this command, of course, through pidyon ha-bein – by giving money to a kohen as “redemption” for the firstborn.
The Torah formulates this command as an obligation to redeem every “peter rechem” – the first child born to a woman. This means that if a child has several older brothers with the same father, but he is his mother’s firstborn, he requires a pidyon ha-bein. Conversely, if a child is his father’s firstborn, but he has several older brothers with the same mother, he is not subject to this obligation. The Ramban, commenting earlier in Parashat Bo (12:30), notes that in light of this halakha, it would seem that the only Egyptian children struck by the plague of the firstborn in Egypt were those who were the firstborns of their mothers. Since the obligation of pidyon ha-bein commemorates, or results from, the plague that befell Egypt, it stands to reason that the obligation pertains only to the kind of firstborns who were killed on the night of the Exodus. It thus follows that on that night God killed only every woman’s first child. An Egyptian child who was his father’s firstborn but not his mother’s was, seemingly, spared from the plague.
However, the Ramban acknowledges that this is not the view taken by Chazal. The Midrash (Midrash Tehillim 105:10) comments that every firstborn Egyptian died, including both firstborns of mothers and firstborns of fathers. Accordingly, the question arises as to why the mitzva of pidyon ha-bein applies only to a “peter rechem” – a woman’s firstborn child. If even firstborns of fathers perished during the plague in Egypt, then why are such firstborns excluded from the obligation of pidyon ha-bein?
The Ramban suggests that the Torah perhaps limited the scope of this obligation because only the firstborns of mothers can be definitively and perceptibly identified as such. Moreover, the Ramban adds, the firstborn animals of the Egyptians also died on the night of the plague (12:29), and in commemoration, the firstborns of certain species of domesticated animals are deemed sacred and subject to special requirements (13:12-13). When it comes to animals, of course, it is usually impossible to identify a male’s firstborn. As such, when God decreed the concept of consecrating firstborns to commemorate the miracle that occurred in Egypt, He limited this institution to firstborns of their mothers. This standard was applied even to humans, in order to maintain a kind of uniform standard.
The question that remains unanswered by the Ramban’s analysis is why the mitzva of pidyon ha-bein does not apply to female firstborns. The Midrash elsewhere (Shemot Rabba 18:3) states explicitly that during the plague of the firstborn God killed even the firstborn females among the Egyptians. Yet, the mitzva of pidyon ha-bein applies only to firstborn males, not females. Seemingly, since this ritual commemorates the survival of Benei Yisrael’s firstborns during the plague that killed the firstborns of Egypt, it should apply to every kind of firstborn that was affected in Egypt, and should thus include females.
Tomorrow we will iy”H explore possible answers to this question.