Ezekiel 43:26

26 Seven days shall they make atonement for the altar and cleanse it, and so consecrate it.

Ezekiel 43:26 In-Context

24 You shall present them before the Lord, and the priests shall throw salt on them and offer them up as a burnt offering to the Lord.
25 For seven days you shall provide daily a goat for a sin offering; also a bull and a ram from the flock, without blemish, shall be provided.
26 Seven days shall they make atonement for the altar and cleanse it, and so consecrate it.
27 When these days are over, then from the eighth day onward the priests shall offer upon the altar your burnt offerings and your offerings of well-being; and I will accept you, says the Lord God.
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.