Exodus 29:35-37

35“Do for Aaron and his sons everything I have commanded you, taking seven days to ordain them. 36Sacrifice a bull each day as a sin offering to make atonement. Purify the altar by making atonement for it, and anoint it to consecrate it.

37For seven days make atonement for the altar and consecrate it. Then the altar will be most holy, and whatever touches it will be holy.