Exodus 17:10 BBE

⁸  Then Amalek came and made war on Israel in Rephidim.

⁹  And Moses said to Joshua, Get together a band of men for us and go out, make war on Amalek: tomorrow I will take my place on the top of the hill with the rod of God in my hand.

¹⁰  So Joshua did as Moses said to him, and went to war with Amalek: and Moses, Aaron, and Hur went up to the top of the hill.

¹¹  Now while Moses' hand was lifted up, Israel was the stronger: but when he let his hand go down, Amalek became the stronger.

¹²  But Moses' hands became tired; so they put a stone under him and he took his seat on it, Aaron and Hur supporting his hands, one on one side and one on the other; so his hands were kept up without falling till the sun went down.