Reference

Exodus 17:16

For he said, Because the Lord hath sworn that the Lord will have war with Amalek from generation to generation.
14

And the Lord said unto Moses, Write this for a memorial in a book, and rehearse it in the ears of Joshua: for I will utterly put out the remembrance of Amalek from under heaven.

15

And Moses built an altar, and called the name of it JEHOVAH–nissi:

16

For he said, Because the Lord hath sworn that the Lord will have war with Amalek from generation to generation.