Exodus 30:17-21

The LORD said to Moses, “Make a bronze bowl, on a bronze stand, for washing. Put the bowl and stand between the Meeting Tent and the altar, and put water in the bowl. Aaron and his sons must wash their hands and feet with the water from this bowl. Each time they enter the Meeting Tent they must wash with water so they will not die. Whenever they approach the altar to serve as priests and offer a sacrifice to the LORD by fire, they must wash their hands and their feet so they will not die. This is a rule which Aaron and his descendants are to keep from now on.”