The Petter Chamor (Hebrew: פטר חמור) or Redemption of the firstborn, is a mitzvah in Judaism in which a male firstborn (bechor) donkey is redeemed by the owner of the donkey, who gives a lamb or kid to a Kohen.
The mitzvah applies to the firstborn male offspring of a Jewish-owned donkey.
The donkey retains a level of holiness and is forbidden for work.
The redemption transfers the holiness to another animal, such as a cow, goat or sheep, so that the donkey can be used for work.
[2] The mitzvah, albeit rare in modern times, is listed as an "obligation of the body"[3] and thus applies in the diaspora as well as the Land of Israel.