Ezekiel 45:18-20

18Thus saith the Lord God; In the first month, in the first day of the month, thou shalt take a young bullock without blemish, and cleanse the sanctuary:

19And the priest shall take of the blood of the sin offering, and put it upon the posts of the house, and upon the four corners of the settle of the altar, and upon the posts of the gate of the inner court.

20And so thou shalt do the seventh day of the month for every one that erreth, and for him that is simple: so shall ye reconcile the house.