Exodus 28:35-37

35It shall be on Aaron 1when he ministers; and its sound shall be heard when he enters and leaves the Holy Place before the Lord, so that he will not die.

36“You shall also make 2a plate of pure gold and engrave on it, like the engravings of a signet, ‘3Holy to the Lord.’ 37You shall 4fasten it on a violet cord, and it shall be on the turban; it shall be at the front of the turban.