Exodus 17:8-16 - Battle With The Amalekites
8 The Amalekites fought Israel at Rephidim. 9 Moses said to Joshua: Choose some of our men. Then fight the Amalekites. Tomorrow I will stand on top of the hill. I will hold in my hand the staff God told me to take along.
10 Joshua did as Moses told him. They fought the Amalekites, while Moses, Aaron, and Hur went to the top of the hill. 11 As long as Moses held up his hands, Israel would win, but as soon as he put his hands down, the Amalekites would start to win. 12 Finally, Moses was so tired that Aaron and Hur got a rock for him to sit on. They stood beside him and supported his arms in the same position until sunset. 13 That is how Joshua defeated the Amalekites.
14 After the fight Jehovah said to Moses: Write an account of this victory and read it to Joshua. I want the Amalekites to be forgotten forever.
15 Moses built an altar. He named it: Jehovah Gives Me Victory. 16 Then Moses explained: This is because I depended on Jehovah. But in future generations, Jehovah will have to fight the Amalekites again.