Exodus 17:14-16

ASV(i) 14 And Jehovah said unto Moses, Write this for a memorial in a book, and rehearse it in the ears of Joshua: that I will utterly blot out the remembrance of Amalek from under heaven. 15 And Moses built an altar, and called the name of it Jehovah-nissi; 16 And he said, Jehovah hath sworn: Jehovah will have war with Amalek from generation to generation.