Exodus 30:19-21

19Aaron and his sons are to wash their hands and their feet there.

20Whenever they go into the Tent of Meeting or come near to the altar to minister, to present an offering made by fire in smoke to Adonai, they are to wash with water so that they do not die.

21They are to wash their hands and their feet, so that they do not die. It is to be an eternal statute for them, to him and to his offspring throughout their generations.”