Exodus 17:9

Moses said unto Joshua— This is the first time mention is made of Joshua, or Jesus, who makes so distinguished a figure in the subsequent part of the sacred history. He is often styled the servant of Moses. Formed under the conduct of that great master, he is appointed general under his direction, and ordered to select proper men to fight with Amalek; while Moses proposes to stand on the hill, with the miraculous rod in his hand, in sight of the warriors, to inspire them with faith and courage; and to teach them and all succeeding generations, that though all human power is weak without the aid of GOD; yet, we should not so rely on that aid, as to omit the use of all rational means. God blesses his people in the use of these. Chosen men were appointed to fight; but they prevailed only while Moses held up his hands, Exodus 17:11.