Exodus 28:36-38

And thou shalt make a plate of pure gold, and grave upon it, like the engravings of a signet, HOLY TO JEHOVAH. And thou shalt put it on a lace of blue, and it shall be upon the mitre; upon the forefront of the mitre it shall be. 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 their holy gifts; and it shall be always upon his forehead, that they may be accepted before Jehovah.