The LORD spoke to Moses, saying: Make a laver of copper and a stand of copper for it, for washing; and place it between the Tent of Meeting and the altar. Put water in it, and let Aaron and his sons wash their hands and feet [in water drawn] from it. When they enter the Tent of Meeting they shall wash with water, that they may not die; or when they approach the altar to serve, to turn into smoke an offering by fire to the LORD, they shall wash their hands and feet, that they may not die. It shall be a law for all time for them—for him and his offspring—throughout the ages.
Exodus 30:17-21