Exodus 29:35-37

35And thus shalt thou do to Aaron, and to his sons, according to all things which I have commanded thee: seven days shalt thou consecrate them. 36And thou shalt offer every day a bull for a sin offering for atonement: and thou shalt cleanse the altar, when thou hast made an atonement for it, and thou shalt anoint it, to sanctify it. 37Seven days thou shalt make an atonement for the altar, and sanctify it; and it shall be an altar most holy: whatever toucheth the altar shall be holy.