Leviticus 16:16

and he shall make an atonement for the Holy Place, the Sanctuary itself being in need of cleansing, because of the uncleanness of the children of Israel, and because of their transgressions in all their sins, for it was exposed to defilement in the midst of a sinful people; and so shall ha do for the Tabernacle of the Congregation, that remaineth among them in the midst of their uncleanness. Thus both the sins of the priests, with which they had contaminated the Sanctuary, and the transgressions of the people, which also defiled the habitation of God in their midst, had to be expiated on the great Day of Atonement.