Exodus 28:36-38 - The Turban
36 "You are to make a medallion of pure gold, and engrave on it "Holy to the LORD,' like the engravings of a signet.
37 You are to put it on a blue cord and place it on the turban. It is to be on the front of the turban 38 and worn on Aaron's forehead in order to take away any guilt contained in the holy things which the Israelis consecrate as holy gifts. It is to remain on his forehead continuously, so they may be accepted in the LORD's presence.