Exodus 12:14-16

‘Now this day will be a memorial to you, and you shall celebrate it as a feast to the LORD; throughout your generations you are to celebrate it as a permanent ordinance. Seven days you shall eat unleavened bread, but on the first day you shall remove leaven from your houses; for whoever eats anything leavened from the first day until the seventh day, that person shall be cut off from Israel. On the first day you shall have a holy assembly, and another holy assembly on the seventh day; no work at all shall be done on them, except what must be eaten by every person, that alone may be prepared by you.