Leviticus 23:6-8

ISV(i) 6 On the fifteenth day of that month is the Festival of Unleavened Bread to the LORD. For seven days you are to eat unleavened bread. 7 On the first day that you hold the sacred assembly, you are to do no servile work. 8 Instead, you are to bring an offering made by fire to the LORD daily for seven days. On the seventh day, you are also to hold a sacred assembly during which you are to do no servile work.”