Leviticus 23:5-8

5The Lord’s Passover begins at twilight on the fourteenth day of the first month. 6On the fifteenth day of that month the Lord’s Festival of Unleavened Bread begins; for seven days you must eat bread made without yeast. 7On the first day hold a sacred assembly and do no regular work. 8For seven days present a food offering to the Lord. And on the seventh day hold a sacred assembly and do no regular work.’ ”