393. Not So Fast!: The prohibition against redeeming firstborn kosher animals

We said, way back in Mitzvah #22, that it is a mitzvah to redeem a firstborn donkey, which is the only non-kosher animal among those whose firstborns are specially dedicated to God. One might assume that that we are likewise supposed to redeem those kosher firstborns that are sanctified to God. This mitzvah tells us otherwise. The firstborns of sheep, goats and cattle are not meant to be redeemed. If one attempted to redeem one of these animals, it didn’t work.

This rule only applies to these three species of domesticated animals, which were also used for Temple sacrifices. The law of firstborns doesn’t apply to the kosher species of wild animals, such as deer.

Even though kohanim and Leviim were not obligated regarding the firstborn of donkeys or of people, they were obligated in this mitzvah. In Temple times, the kohein who received the firstborn animal was not permitted to sell it, since it was intended as a sacrifice. In non-Temple times, it is meant to be eaten, so he is permitted to sell it, even to a non-kohein. (A firstborn with a defect could not be used as a sacrifice and was sold even in Temple times.)

The reason for this mitzvah, as we have said, is that God spared the Jews and their animals when he slew the firstborn in Egypt. Since the firstborn of humans, flocks and herds were all spared, all of these are dedicated to God in this fashion.

This mitzvah applies in Israel at all times. In the Talmud, it is discussed in the tractate of Temurah (5b, 21a) and in the first chapter of tractate Bechoros. It is codified in the Shulchan Aruch in Yoreh Deah 310. This mitzvah is #108 of the 365 negative mitzvos in the Rambam’s Sefer HaMitzvos and #109 of the 194 negative mitzvos that can be observed today in the Chofetz Chaim’s Sefer HaMitzvos HaKatzar.