Leviticus 8:13-15
English Standard Version
14Then he brought the bull of the sin offering, and Aaron and his sons laid their hands on the head of the bull of the sin offering.
15And he killed it, and Moses took the blood, and with his finger put it on the horns of the altar around it and purified the altar and poured out the blood at the base of the altar and consecrated it to make atonement for it.