Numbers 31:4-8

You shall send a thousand from each tribe of all the tribes of Israel to the war.”

So there were selected from the thousands of Israel, a thousand from each tribe, twelve thousand armed for war.

And Moses sent them, a thousand from each tribe, to the war, and Phinehas the son of Eleazar the priest, to the war with them, and the holy implements and the trumpets for the alarm in his hand.

So they made war against Midian, just as the Lord had commanded Moses, and they killed every male.

They killed the kings of Midian along with the rest of those killed: Evi, Rekem, Zur, Hur, and Reba, the five kings of Midian. They also killed Balaam the son of Beor with the sword.