Leviticus 23:27-28

Howbeit on the tenth day of this seventh month is the day of atonement: it shall be a holy convocation unto you, and ye shall afflict your souls; and ye shall offer an offering made by fire unto Jehovah. And ye shall do no manner of work in that same day; for it is a day of atonement, to make atonement for you before Jehovah your God.