Exodus 17:12
17:12 When the hands of Moses became heavy, they took a stone and put it under him, and Aaron and Hur held up his hands, one on one side and one on the other, and so his hands were steady until the sun went down.
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.”