Leviticus 23:26-32

The LORD said to Moses, “The tenth day of this seventh month is the Day of Atonement. Hold a sacred assembly and deny yourselves, and present a food offering to the LORD. Do not do any work on that day, because it is the Day of Atonement, when atonement is made for you before the LORD your God. Those who do not deny themselves on that day must be cut off from their people. I will destroy from among their people anyone who does any work on that day. You shall do no work at all. This is to be a lasting ordinance for the generations to come, wherever you live. It is a day of sabbath rest for you, and you must deny yourselves. From the evening of the ninth day of the month until the following evening you are to observe your sabbath.”