Exodus 17:14-16

King James Version

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 Jehovahnissi:

¹⁶ For he said, Because the Lord hath sworn that the Lord will have war with Amalek from generation to generation.