Exodus 17:15

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

And Moses built an altar, and called the name of it Jehovahnissi:

A description of Moses building an altar.

Context

13And Joshua discomfited Amalek and his people with the edge of the sword.

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.