Exodus 28:41-43

Young's Literal Translation

⁴¹ and thou hast clothed Aaron thy brother with them, and his sons with him, and hast anointed them, and hast consecrated their hand, and hast sanctified them, and they have been priests to Me.

⁴² `And make thou for them linen trousers to cover the naked flesh: they are from the loins even unto the thighs;

⁴³ and they have been on Aaron and on his sons, in their going in unto the tent of meeting, or in their drawing nigh unto the altar to minister in the sanctuary, and they do not bear iniquity nor have they died; a statute age-during to him, and to his seed after him.