Ezekiel 45:18-20

Young's Literal Translation

¹⁸ `Thus said the Lord Jehovah: In the first [month], in the first of the month, thou dost take a bullock, a son of the herd, a perfect one, and hast cleansed the sanctuary:

¹⁹ and the priest hath taken of the blood of the sin offering, and hath put on the door-post of the house, and on the four corners of the border of the altar, and on the post of the gate of the inner court.

²⁰ And so thou dost do on the seventh of the month, because of each erring one, and because of the simple one -- and ye have purified the house.