Exodus 13:5-9

5When the Lord brings you to the land of the Canaanites, Hittites, Amorites, Hivites, and Jebusites, which he swore to your fathers to give you, a land flowing with milk and honey, then you will keep this ceremony in this month.

6For seven days you must eat bread made without yeast, and on the seventh day there is to be a festival to the Lord.

7Bread made without yeast must be eaten for seven days; no bread made with yeast shall be seen among you, and you must have no yeast among you within any of your borders.

8You are to tell your son on that day, ‘It is because of what the Lord did for me when I came out of Egypt.’

9It will be a sign for you on your hand and a memorial on your forehead, so that the law of the Lord may be in your mouth, for with a mighty hand the Lord brought you out of Egypt.