Deuteronomy 11:16-21

Take care lest your heart be deceived, and you turn aside and serve other gods and worship them; then the anger of the LORD will be kindled against you, and he will shut up the heavens, so that there will be no rain, and the land will yield no fruit, and you will perish quickly off the good land that the LORD is giving you. “You shall therefore lay up these words of mine in your heart and in your soul, and you shall bind them as a sign on your hand, and they shall be as frontlets between your eyes. You shall teach them to your children, talking of them when you are sitting in your house, and when you are walking by the way, and when you lie down, and when you rise. You shall write them on the doorposts of your house and on your gates, that your days and the days of your children may be multiplied in the land that the LORD swore to your fathers to give them, as long as the heavens are above the earth.