What Does Exodus 17:10 Mean?

So Joshua did as Moses told him, and fought with Amalek, while Moses, Aaron, and Hur went up to the top of the hill.

Joshua's immediate compliance, "did as Moses told him", sets the tone for Joshua's character across the entire Moses-Joshua relationship: the subordinate who does exactly what the leader commands, without delay or qualification. Joshua's compliance-faithfulness makes him the ideal successor to the compliance-faithful Moses (the tabernacle compliance formula "as the LORD commanded Moses" mirrors "Joshua did as Moses told him"). The leader who expresses radical compliance is the one who can be trusted with increasing responsibility.

Aaron and Hur accompany Moses to the hilltop as the intercessory prayer witnesses: the same principle that sent the elders to the water-from-rock miracle (verse 5) sends Aaron and Hur to Moses' prayer-hilltop. Aaron is the high priest; Hur (Jewish tradition identifies him as Miriam's husband or Caleb's son) is a recognized leader. The two support figures on the hilltop are the intercessory prayer's human helpers: as the wilderness theology of shared responsibility requires: Moses does not pray alone; the community's leaders join his intercession.

The hilltop tripartite (Moses-Aaron-Hur) mirrors and contrasts with the battlefield: Joshua-Israel-Amalek below, Moses-Aaron-Hur above. The battle has two theaters: the physical combat of the valley and the prophetic intercession of the hilltop. Both are necessary to the outcome; neither theater alone is sufficient. The battle theology of Rephidim is not "prayer instead of fighting" or "fighting instead of prayer" but "fighting and praying simultaneously and interdependently."