Exodus 30:19–21

19 Aaron and his sons must wash their hands and feet from the basin. 20 Whenever they enter the tent of meeting or approach the altar to minister by burning a food offering to the Lord, they must wash with water so that they will not die. 21 They must wash their hands and feet so that they will not die; this is to be a permanent statuteo for them, for Aaron and his descendants throughout their generations.”