Leviticus 23:5-8

The LORD’s Passover begins at twilight on the fourteenth day of the first month. On the fifteenth day of that month the LORD’s Festival of Unleavened Bread begins; for seven days you must eat bread made without yeast. On the first day hold a sacred assembly and do no regular work. For seven days present a food offering to the LORD. And on the seventh day hold a sacred assembly and do no regular work.’ ”