Leviticus 9:7-9

King James Version

⁷ And Moses said unto Aaron, Go unto the altar, and offer thy sin offering, and thy burnt offering, and make an atonement for thyself, and for the people: and offer the offering of the people, and make an atonement for them; as the Lord commanded.

⁸ Aaron therefore went unto the altar, and slew the calf of the sin offering, which was for himself.

⁹ And the sons of Aaron brought the blood unto him: and he dipped his finger in the blood, and put it upon the horns of the altar, and poured out the blood at the bottom of the altar: