Exodus 30:18-20

18‘Use bronze to make a large bowl for water. Also use bronze to make a base for it to stand on. Put it between the Tent of Meeting and the altar. Fill it with water.

19Aaron and his sons must use the water from the bowl to wash their hands and their feet.

20Every time they go into the Tent of Meeting, they must wash in the same way. Then they will not die. They must also wash before they go to the altar to make a burnt offering to the Lord.