Leviticus 16:29-34

And it shall be a statute for ever unto you: in the seventh month, on the tenth day of the month, ye shall afflict your souls, and shall do no manner of work, the home-born, or the stranger that sojourneth among you: for on this day shall atonement be made for you, to cleanse you; from all your sins shall ye be clean before Jehovah. It is a sabbath of solemn rest unto you, and ye shall afflict your souls; it is a statute for ever. And the priest, who shall be anointed and who shall be consecrated to be priest in his father’s stead, shall make the atonement, and shall put on the linen garments, even the holy garments: and 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. And this shall be an everlasting statute unto you, to make atonement for the children of Israel because of all their sins once in the year. And he did as Jehovah commanded Moses.