Leviticus 9:6

You shall speak to the children of Israel, saying, ‘Take a male goat for a sin offering; and a calf and a lamb, both a year old, without defect, for a burnt offering;

and a bull and a ram for peace offerings, to sacrifice before the LORD; and a meal offering mixed with oil: for today the LORD appears to you.’”

They brought what Moses commanded before the Tent of Meeting. All the congregation came near and stood before the LORD.

Moses said to Aaron, “Draw near to the altar, and offer your sin offering, and your burnt offering, and make atonement for yourself, and for the people; and offer the offering of the people, and make atonement for them, as the LORD commanded.”

So Aaron came near to the altar, and killed the calf of the sin offering, which was for himself.

The sons of Aaron presented the blood to him; and he dipped his finger in the blood, and put it on the horns of the altar, and poured out the blood at the base of the altar;