Leviticus 9:6-9

⁶And Moses said, This is the thing which the LORD commanded that ye should do: and the glory of the LORD shall appear to you.

⁷And Moses said to Aaron, Go to 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.

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

⁹And the sons of Aaron brought the blood to 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: