Exodus 29:35-37

35And thus shalt thou do to Aaron, and to his sons, according to all that I have commanded thee: seven days shalt thou consecrate them.

36And thou shalt offer every day a bullock as a sin-offering for atonement; and the altar shalt thou cleanse from sin, by making atonement for it, and shalt anoint it, to hallow it.

37Seven days shalt thou make atonement for the altar and hallow it; and the altar shall be most holy: whatever toucheth the altar shall be holy.