3,680. Two Babies; Two Wives

Hilchos Bikkurim 11:20

Let’s say that someone’s wife has never given birth before. She gives birth to a boy and a girl, but we don’t know which was born first. In such a case, one need not pay a kohein. If she gives birth to two boys, the father must give five sela to a kohein even if we don’t which baby was born first. If one of the sons dies within thirty days, the father need not pay because of the rule that the burden of proof is on the one who wants to take property from another (i.e., the kohein must prove that the live child is the firstborn). If the father died, five sela must be paid to a kohein. This is so regardless of whether the father died within thirty days of the sons’ birth or later, and regardless of whether his heirs already divided the estate, because the father’s property was already obligated to make this payment.

Hilchos Bikkurim 11:21

Let’s say that a man has two wives, neither of whom has given birth before. They give birth to two sons (one each) and the father gives ten sela (five for each son) to a kohein within thirty days of their birth. If one of the babies dies within thirty days and he gave the ten sela to one kohein, the kohein should return five sela to him. If the father gave two kohanim five sela each, he can’t retrieve any money from them because he didn’t specify which son he was redeeming with which kohein. Therefore, each of them can tell him to go collect it from the other.