Ex 13:6-10 Seven days you shall eat unleavened bread, and on the seventh day there shall be a feast to the Lord. Unleavened bread shall be eaten seven days. And no leavened bread shall be seen among you, nor shall leaven be seen among you in all your quarters. And you shall tell your son in that day, saying, ‘This is done because of what the Lord did for me when I came up from Egypt. It shall be as a sign to you on your hand and as a memorial between your eyes, that the Lord’s law may be in your mouth; for with a strong hand the Lord has brought you out of Egypt. You shall therefore keep this ordinance in its season from year to year.
Lev 23:6-8 On the fifteenth day of the same month is the Feast of Unleavened Bread to the Lord; seven days you must eat unleavened bread. On the first day you shall have a holy convocation; you shall do no customary work on it. But you shall offer an offering made by fire to the Lord for seven days. The seventh day shall be a holy convocation; you shall do no customary work on it.'”