Leviticus 5:8-10
8 He is to bring them to the priest, who shall first offer the one for the sin offering. He is to wring its head from its neck, not severing it completely,
9 and is to sprinkle some of the blood of the sin offering against the side of the altar; the rest of the blood must be drained out at the base of the altar. It is a sin offering.
10 The priest shall then offer the other as a burnt offering in the prescribed way and make atonement for him for the sin he has committed, and he will be forgiven.