Exodus 30:19-21

19And Aaron and his sons shall wash their hands and their feet out of it.

20When they go into the tent of meeting, they shall wash with water, that they may not die; or when they come near to the altar to serve, to burn an offering by fire to Jehovah.

21And they shall wash their hands and their feet, that they may not die; and it shall be an everlasting statute for them, for him and for his seed throughout their generations.