Leviticus 9:6-9

⁶Moses said: This is the word, which the Lord hath commanded: do it, and his glory will appear to you.

⁷And he said to Aaron: Approach to the altar, and offer sacrifice for thy sin: offer the holocaust, and pray for thyself and for the people: and when thou hast slain the people’s victim, pray for them, as the Lord hath commanded.

⁸And forthwith Aaron, approaching to the altar, immolated the calf for his sin:

⁹And his sons brought him the blood of it: and he dipped his finger therein, and touched the horns of the altar, and poured the rest at the foot thereof.