Moses
Exodus 17:10ESV·traditional attribution

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

John Calvin Reformed @genevareformer

10. So Joshua did as. Although Joshua is by no means backward, but diligently executes what he knows to be commanded him by God Himself, and it is probable that the soldiers whom he had taken to accompany him did their duty properly, yet is it expressly stated that they gained the victory by no care, or striving, or courage of their own, but by...

Matthew Henry Presbyterian @wholebiblehenry

We have here the story of the war with Amalek, which, we may suppose, was the first that was recorded in the book of the wars of the Lord, Num 21:14. Amalek was the first of the nations that Israel fought with, Num 24:20. Observe, I. Amalek's attempt: They came out, and fought with Israel, Exo 17:8.

Commenting on Exodus 17:8-16

John Gill Reformed Baptist @doctorgill

So Joshua did as Moses had said to him,.... He singled out some proper persons for the battle, and arrayed them with armour, and led them forth out of the camp, and went forth at the head of them: and fought with Amalek; upon both armies meeting, a battle ensued: and Moses, Aaron, and Hur, went up to the top of the hill; to the...