Ezekiel 43:25-27

25Seven days shalt thou prepare every day a goat for a sin offering: they shall also prepare a young bull, and a ram out of the flock, without blemish. 26Seven days shall they purge the altar and purify it; and they shall consecrate themselves.1 27And when these days are fulfilled, it shall be, that upon the eighth day, and so onward, the priests shall make your burnt offerings upon the altar, and your peace offerings; and I will accept you, saith the Lord GOD.2