Leviticus 23:27-28

²⁷Also on the tenth day of this seventh month there shall be a day of atonement; it shall be a holy convocation to you, and ye shall afflict your souls, and offer an offering made by fire to the LORD.

²⁸And ye shall do no work in that same day; for it is a day of atonement, to make an atonement for you before the LORD your God.