Exodus 17:14-16

After the victory, the LORD instructed Moses, “Write this down on a scroll as a permanent reminder, and read it aloud to Joshua: I will erase the memory of Amalek from under heaven.” Moses built an altar there and named it Yahweh-Nissi (which means “the LORD is my banner”). He said, “They have raised their fist against the LORD’s throne, so now the LORD will be at war with Amalek generation after generation.”