Exodus 29:37 in the World English Bible
Seven days you shall make atonement for the altar, and sanctify it; and the altar shall be most holy. Whatever touches the altar shall be holy.
Context
36 And thou shalt offer every day a bullock 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.
37 Seven days thou shalt make an atonement for the altar, and sanctify it; and it shall be an altar most holy: whatsoever toucheth the altar shall be holy.
38 Now this is that which thou shalt offer upon the altar; two lambs of the first year day by day continually.