Leviticus 9:8-9, 18

So Aaron approached the altar and killed the calf as the sin offering, which was designated for himself. The sons of Aaron presented the blood to him; he dipped his finger in the blood and put some of it on the horns of the altar, and poured out the rest of the blood at the altar’s base

He also killed the bull and the ram, the sacrifice of peace offerings which was for the people; and Aaron’s sons handed the blood to him and he sprinkled it around on the altar