Exodus 28:36-38 - The Turban
36 “You are to make a pure gold medallion and engrave it, like the engraving of a seal:
HOLY TO THE LORD.
37 Fasten it to a cord of blue yarn so it can be placed on the turban; the medallion is to be on the front of the turban. 38 It will be on Aaron’s forehead so that Aaron may bear the guilt