For he said, Because the LORD hath sworn that the LORD will have war with Amalek from generation to generation.
A declaration made by Moses after a battle.
Exodus 17:16
King James Version (public domain)
Traditionally attributed to Moses · c. 13th century BC · The Pentateuch — Genesis, Exodus, Leviticus, Numbers, and Deuteronomy — is traditionally attributed to him
Context
14And 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.
15And Moses built an altar, and called the name of it Jehovahnissi:
16For he said, Because the LORD hath sworn that the LORD will have war with Amalek from generation to generation.