‏ Leviticus 23:27-29

27Now aon the tenth day of this seventh month is the Day of Atonement. It shall be for you a time of holy convocation, and you shall afflict yourselves
Or  shall fast; also verse 32
and present a food offering to the Lord.
28And you shall not do any work on that very day, for it is a Day of Atonement, to make atonement for you before the Lord your God. 29For whoever is not afflicted on that very day cshall be cut off from his people.
Copyright information for ESV