Exodus 28:39-40, 43

“You shall weave the tunic of checkered work of fine linen, and make a turban of fine linen. You shall make a sash, the work of an embroiderer. “For Aaron’s sons you shall make tunics and sashes and [ornamental] caps, for glory and honor and beauty.

The various articles of clothing shall be on Aaron and on his sons when they enter the Tent of Meeting, or when they approach the altar [of incense] to minister in the Holy Place, so that they do not incur guilt and die. It shall be a statute forever to Aaron and to his descendants after him.