Leviticus 23:6-8

And on the fifteenth day of the same month is the feast of unleavened bread unto Jehovah: seven days ye shall eat unleavened bread. In the first day ye shall have a holy convocation: ye shall do no servile work. But ye shall offer an offering made by fire unto Jehovah seven days: in the seventh day is a holy convocation; ye shall do no servile work.