Leviticus 16
18 Ref And he is to go out to the altar which is before the Lord and make it free from sin; and he is to take some of the blood of the ox and the blood of the goat and put it on the horns of the altar and round it;
19 Ref Shaking drops of the blood from his finger on it seven times to make it holy and clean from whatever is unclean among the children of Israel.
20 Ref And when he has done whatever is necessary to make the holy place and the Tent of meeting and the altar free from sin, let him put the living goat before the Lord;