29 “This is to be a lasting ordinance for you: On the tenth day of the seventh month you must deny yourselves and not do any work—whether native-born or an alien living among you— 30 because on this day atonement will be made for you, to cleanse you. Then, before the LORD, you will be clean from all your sins. 31 It is a sabbath of rest, and you must deny yourselves; it is a lasting ordinance. 32 The priest who is anointed and ordained to succeed his father as high priest is to make atonement. He is to put on the sacred linen garments 33 and make atonement for the Most Holy Place, for the Tent of Meeting and the altar, and for the priests and all the people of the community.
34 “This is to be a lasting ordinance for you: Atonement is to be made once a year for all the sins of the Israelites.”
And it was done, as the LORD commanded Moses.
(Leviticus 16:29-34)