Leviticus 1:14-16

14And if the burnt sacrifice for his offering to the LORD shall be of fowls, then he shall bring his offering of turtledoves, or of young pigeons. 15And the priest shall bring it to the altar, and wring off its head, and burn it on the altar; and its blood shall be wrung out at the side of the altar:1 16And he shall pluck away its crop with its feathers, and cast it beside the altar on the east part, by the place of the ashes:2