Exodus 17:13-16 New American Standard Bible (NASB)

13. So Joshua overwhelmed Amalek and his people with the edge of the sword.

14. Then the Lord said to Moses, "Write this in a book as a memorial and recite it to Joshua, that I will utterly blot out the memory of Amalek from under heaven."

15. Moses built an altar and named it The Lord is My Banner;

16. and he said, "The Lord has sworn; the Lord will have war against Amalek from generation to generation."

Exodus 17