Bekhorot (“Firstborns”) is a tractate in Seder Kodashim (“Order of Holy Things") that discusses three categories of firstborns: a woman’s firstborn son, the male firstborn of a kosher domesticated animal, and a male firstborn donkey. The Torah assigns a sacred status to each of these and requires them to be consecrated - either through transfer to a priest, redemption, or sacrifice, depending on the firstborn and the circumstances. Bekhorot discusses details of this process, such as determining whether an animal is a firstborn in questionable cases and blemishes that disqualify a firstborn animal from being sacrificed in the Temple.