Exodus 30:17-21 NRS

17 The Lord spoke to Moses:
18 You shall make a bronze basin with a bronze stand for washing. You shall put it between the tent of meeting and the altar, and you shall put water in it;
19 with the water a Aaron and his sons shall wash their hands and their feet.

References for Exodus 30:19

      20 When they go into the tent of meeting, or when they come near the altar to minister, to make an offering by fire to the Lord, they shall wash with water, so that they may not die.
      21 They shall wash their hands and their feet, so that they may not die: it shall be a perpetual ordinance for them, for him and for his descendants throughout their generations.