Leviticus 1:13-15

13 You are to wash the internal organs and the legs with water, and the priest is to bring all of them and burn them on the altar. It is a burnt offering, a food offering, an aroma pleasing to the LORD.

14 “ ‘If the offering to the LORD is a burnt offering of birds, you are to offer a dove or a young pigeon.

15 The priest shall bring it to the altar, wring off the head and burn it on the altar; its blood shall be drained out on the side of the altar.