Leviticus 4:34-35

New Revised Standard Version Catholic Edition

³⁴ 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. ³⁵ You shall remove all its fat, as the fat of the sheep is removed from the sacrifice of well-being, and the priest shall turn it into smoke on the altar, with the offerings by fire to the Lord. Thus the priest shall make atonement on your behalf for the sin that you have committed, and you shall be forgiven.