Exodus 28:36-39

36"You shall make a plate of pure gold and engrave on it, like the engraving of a signet, 'Holy to the Lord.'

37And you shall fasten it on the turban by a cord of blue. It shall be on the front of the turban.

38It shall be on Aaron's forehead, and Aaron shall bear any guilt from the holy things that the people of Israel consecrate as their holy gifts. It shall regularly be on his forehead, that they may be accepted before the Lord.

39"You shall weave the coat in checker work of fine linen, and you shall make a turban of fine linen, and you shall make a sash embroidered with needlework.