Bechoros 8:5-6
Bechoros 8:5
Let's say that the wives of two different men – neither of whom had given birth before – gave birth to two boys (and they got mixed up), then each father pays five sela to a kohein (because each is invariably the father of a firstborn). If one of the babies died within 30 days and they had already given the money to the same kohein, he must refund them five sela (which they split). If the fathers gave the money to two different kohanim, they can’t recoup what they paid. If the women gave birth to a boy and a girl, the fathers are exempt (because we don’t know who’s responsible) and the boy must redeem himself (when he’s older, since he’s certainly a firstborn). If the women gave birth to two girls and a boy, or two boys and two girl, the kohein isn’t entitled to anything.
Bechoros 8:6
If one of the two women married to two different men had given birth before and the other hadn’t and they gave birth to two boys, then the one whose wife had never given birth before must give five sela to a kohein; if they gave birth to a boy and a girl, the kohein isn’t entitled to anything. If the boy died within 30 days and the father had already given the money to the kohein, the kohein must return the five sela (because the child wasn’t viable); after 30 days, even if the father hasn’t already given the money to a kohein, he must do so (because the child was viable, and therefore obligated). If the child died on the thirtieth day, it’s the same as on the day before (i.e., “30 days” is inclusive). Rabbi Akiva says that if the father already gave the money, it is not refunded; if he did not yet give, he need not do so. If the father died within 30 days, the child is assumed not to have been redeemed unless he can produce proof that he was; if the father died after 30 days, the child is assumed to have been redeemed unless they deliver a deathbed statement from the father to the contrary. If a man and his son both need to be redeemed, the father should redeem himself first. Rabbi Yehuda says that he should redeem his son first because his father was obligated to redeem him while he himself is obligated to redeem his son.