Leviticus 4:25-26

25Then the priest shall take some of the blood of the sin offering with his finger and put it on the horns of the altar of burnt offering and pour out the rest of its blood at the base of the altar of burnt offering.

26And all its fat he shall burn on the altar, like the fat of the sacrifice of peace offerings. So the priest shall make atonement for him for his sin, and he shall be forgiven.