Leviticus 23:4-8

‘These are the appointed times of the LORD, holy convocations which you shall proclaim at the times appointed for them. In the first month, on the fourteenth day of the month at twilight is the LORD’S Passover. Then on the fifteenth day of the same month there is the Feast of Unleavened Bread to the LORD; for seven days you shall eat unleavened bread. On the first day you shall have a holy convocation; you shall not do any laborious work. But for seven days you shall present an offering by fire to the LORD. On the seventh day is a holy convocation; you shall not do any laborious work.’ ”