Leviticus 16:31-34

³¹It is a Sabbath of solemn rest to you, and you shall afflict your souls. It is a statute forever.

³²The priest, who is anointed and who is consecrated to be priest in his father’s place, shall make the atonement, and shall put on the linen garments, even the holy garments.

³³Then he shall make atonement for the Holy Sanctuary; and he shall make atonement for the Tent of Meeting and for the altar; and he shall make atonement for the priests and for all the people of the assembly.

³⁴“This shall be an everlasting statute for you, to make atonement for the children of Israel once in the year because of all their sins.” It was done as the LORD commanded Moses.