Leviticus 16:29-34 (NKJV)
29 “This shall be a statute forever for you: In the seventh month, on the tenth day of the month, you shall afflict your souls, and do no work at all, whether a native of your own country or a stranger who dwells among you. 30 For on that day the priest shall make atonement for you, to cleanse you, that you may be clean from all your sins before the Lord. 31 It is a sabbath of solemn rest for you, and you shall afflict your souls. It is a statute forever. 32 And the priest, who is anointed and consecrated to minister as priest in his father’s place, shall make atonement, and put on the linen clothes, the holy garments; 33 then he shall make atonement for the Holy Sanctuary, and he shall make atonement for the tabernacle 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, for all their sins, once a year.” And he did as the Lord commanded Moses.