Jerome : (Verses 26-27) And after he has been cleansed, seven days shall be numbered for him, and on the day of his entrance into the sanctuary and into the inner courtyard, to minister unto me in the sanctuary, he shall offer a sin-offering unto the Lord God (or he shall offer an atonement). But after the priest has been purified according to the order of purification that is prescribed in the Mosaic law, let seven days be numbered for him, either the perfect number of penance, or after the consummation of the world, when we pass over to the true ogdoad, so that he may enter the holy of holies (which is the inner courtyard) and minister in the sanctuary and always offer a victim for the sin of conscience: and let there be no time when he does not remember that he has been defiled by his father and mother, son and daughter, brother and sister. For indeed we are compelled to do many things in the constraints of this world, either due to the condition of the flesh or the frailty of nature. — Commentary on Ezekiel