Leviticus 23:6-8

The Feast of Unleavened Bread begins on the fifteenth day of the same month. You will eat bread made without yeast for seven days. On the first day of this feast you will have a holy meeting, and you must not do any work. For seven days you will bring an offering made by fire to the LORD. There will be a holy meeting on the seventh day, and on that day you must not do any regular work.’ ”