Leviticus 4:17-18, 25

and the priest shall dip his finger in the blood, and sprinkle it seven times before Jehovah, before the veil. And he shall put of the blood upon the horns of the altar which is before Jehovah, that is in the tent of meeting; and all the blood shall he pour out at the base of the altar of burnt-offering, which is at the door of the tent of meeting.

And the priest shall take of the blood of the sin-offering with his finger, and put it upon the horns of the altar of burnt-offering; and the blood thereof shall he pour out at the base of the altar of burnt-offering.