‘May God Avenge Their Blood’

Remember what Amalek did unto thee by the way as ye came forth out of Egypt; how he met thee by the way, and smote the hindmost of thee, all that were enfeebled in thy rear, when thou wast faint and weary; and he feared not God. — Deuteronomy 25

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

And Moses built an altar, and called the name of it “God is my battle-standard [Adonai nissi].”