Leviticus 23:4-8

4“‘These are the Lord’s appointed times, holy assemblies, which you must proclaim at their appointed time.

5In the first month, on the fourteenth day of the month, at twilight, is a Passover offering to the Lord.

6Then on the fifteenth day of the same month will be the festival of unleavened bread to the Lord; seven days you must eat unleavened bread.

7On the first day there will be a holy assembly for you; you must not do any regular work.

8You must present a gift to the Lord for seven days, and the seventh day is a holy assembly; you must not do any regular work.’”