Leviticus 23:23-32

GOD said to Moses: “Tell the People of Israel, On the first day of the seventh month, set aside a day of rest, a sacred assembly—mark it with loud blasts on the ram’s horn. Don’t do any ordinary work. Offer a Fire-Gift to GOD.” GOD said to Moses: “The tenth day of the seventh month is the Day of Atonement. Hold a sacred assembly, fast, and offer a Fire-Gift to GOD. Don’t work on that day because it is a day of atonement to make atonement for you before your GOD. Anyone who doesn’t fast on that day must be cut off from his people. I will destroy from among his people anyone who works on that day. Don’t do any work that day—none. This is a perpetual decree for all the generations to come, wherever you happen to be living. It is a Sabbath of complete and total rest, a fast day. Observe your Sabbath from the evening of the ninth day of the month until the following evening.”