Exodus 24:14

24:14 He told the elders, “Wait for us in this place until we return to you. Here are Aaron and Hur with you. Whoever has any matters of dispute can approach them.”

Exodus 30:20

30:20 When they enter the tent of meeting, they must wash with water so that they do not die. Also, when they approach the altar to minister by burning incense as an offering made by fire to the Lord,