Exodus 28:42-43

New Living Translation

⁴² Also make linen undergarments for them, to be worn next to their bodies, reaching from their hips to their thighs. ⁴³ These must be worn whenever Aaron and his sons enter the Tabernacle^[a] or approach the altar in the Holy Place to perform their priestly duties. Then they will not incur guilt and die. This is a permanent law for Aaron and all his descendants after him.