Exodus 30:20-22

American Standard Version

²⁰ when they go into the tent of meeting, they shall wash with water, that they die not; or when they come near to the altar to minister, to burn an offering made by fire unto Jehovah. ²¹ So they shall wash their hands and their feet, that they die not: and it shall be a statute for ever to them, even to him and to his seed throughout their generations.

²² Moreover Jehovah spake unto Moses, saying,