Exodus 28:37-39

New Revised Standard Version, Anglicised Catholic Edition

³⁷ You shall fasten it on the turban with a blue cord; it shall be on the front of the turban. ³⁸ It shall be on Aaron’s forehead, and Aaron shall take on himself any guilt incurred in the holy offering that the Israelites consecrate as their sacred donations; it shall always be on his forehead, in order that they may find favour before the Lord.

³⁹ You shall make the chequered tunic of fine linen, and you shall make a turban of fine linen, and you shall make a sash embroidered with needlework.