Exodus 28:36-38 - The Turban
36 "And you will make a pure gold rosette, and you will engrave on it with seal engravings: "A holy object for Yahweh."
37 And you will place it on a blue cord, and it will be on the turban, at the front of the turban it will be. 38 And it will be on the forehead of Aaron, and Aaron will bear the guilt of the holy objects that the {Israelites} will consecrate for all their holy gifts, and it will be on his forehead continually for acceptance for them before Yahweh.