Deuteronomy 6:7-9

6:7 and you must teach them to your children and speak of them as you sit in your house, as you walk along the road, as you lie down, and as you get up. 6:8 You should tie them as a reminder on your forearm and fasten them as symbols on your forehead. 6:9 Inscribe them on the doorframes of your houses and gates.