Leviticus 23:5

3“‘Six days shall work be done, but on the seventh day is a Sabbath of solemn rest, a holy convocation; you shall do no kind of work. It is a Sabbath to the LORD in all your dwellings.

4“‘These are the set feasts of the LORD, even holy convocations, which you shall proclaim in their appointed season.

5In the first month, on the fourteenth day of the month in the evening, is the LORD’s Passover.

6On the fifteenth day of the same month is the feast of unleavened bread to the LORD. Seven days you shall eat unleavened bread.

7In the first day you shall have a holy convocation. You shall do no regular work.