Exodus 13:8-10

New Revised Standard Version, Anglicised

⁸ You shall tell your child on that day, “It is because of what the Lord did for me when I came out of Egypt.” ⁹ It shall serve for you as a sign on your hand and as a reminder on your forehead, so that the teaching of the Lord may be on your lips; for with a strong hand the Lord brought you out of Egypt. ¹⁰ You shall keep this ordinance at its proper time from year to year.