Exodus 28:38

28:38 It will be on Aaron’s forehead, and Aaron will bear the iniquity of the holy things, which the Israelites are to sanctify by all their holy gifts; it will always be on his forehead, for their acceptance before the Lord.

Exodus 13:9

13:9 It 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.