Exodus 17:9-11

Young's Literal Translation

⁹ and Moses saith unto Joshua, `Choose for us men, and go out, fight with Amalek: to-morrow I am standing on the top of the hill, and the rod of God in my hand.'

¹⁰ And Joshua doth as Moses hath said to him, to fight with Amalek, and Moses, Aaron, and Hur, have gone up [to] the top of the height;

¹¹ and it hath come to pass, when Moses lifteth up his hand, that Israel hath been mighty, and when he letteth his hands rest, that Amalek hath been mighty.