Charles Ellicott Commentary Ezekiel 45:18

"Thus saith the Lord Jehovah: In the first [month], in the first [day] of the month, thou shalt take a young bullock without blemish; and thou shalt cleanse the sanctuary." — Ezekiel 45:18 (ASV)

In the first month, in the first day of the month— The rest of this and the first fifteen verses of the following chapter are occupied with the ritual of the sacrifices on certain special occasions. In each case the deviations from the Mosaic law are remarkable, as well as the omission of any mention of the Feast of Weeks (Pentecost) and of the Great Day of Atonement. Ezekiel, as a priest, must have been familiar with the law in these matters, and therefore the changes he introduces must have been intentional.

Like the changes in the division of the land, they seemed designed to show that this was an ideal vision. No attempt was ever made to follow the arrangements here laid down. The Mosaic law prescribed (in addition to the burnt offerings and grain offerings) a sin offering, which was to be a male goat (Numbers 28:15) for the first of every month; also on the tenth day of the seventh month, on the Great Day of Atonement, two male goats (one for the “scapegoat”) were to be offered.

Of all these Ezekiel mentions only the sin offering for the beginning of the first month, and also for the seventh day of the same, which the Mosaic law does not mention; but he provides for these bullocks instead of goats. In the ritual of the blood he makes a corresponding change. The law gives no special directions for the sprinkling of the blood of the sin offerings on the first of each month, because they were included in the ordinary rule (Leviticus 4:25, 30, and so on) of sprinkling upon the sides of the altar of burnt offering; only in the case of the sin offering for the high priest or for the whole congregation (when the victim was a bullock) was the blood brought within the Temple itself, and sprinkled seven times before the veil, and applied to the horns of the altar of incense.

On the Day of Atonement it was carried into the Holy of Holies, and sprinkled upon and before the mercy seat. All this is here changed. Some of the blood of these sin offerings (Ezekiel 45:19) is to be put upon the posts of the house , upon the corners of the settle of the altar, and upon the posts of the gate of the inner court.