Exodus 28:36-38 - The Turban
36 And thou shalt make a thin plate of pure gold, and engrave on it, as the engravings of a seal, Holiness to Jehovah!
37 And thou shalt put it on a lace of blue, and it shall be upon the turban upon the front of the turban shall it be. 38 And it shall be upon Aaron's forehead, and Aaron shall bear the iniquity of the holy things, which the children of Israel shall hallow in all gifts of their holy things; and it shall be continually on his forehead, that they may be accepted before Jehovah.