Numbers 31:5

2 Give the Midianites punishment for the wrong they did to the children of Israel: and after that you will go to rest with your people.

3 So Moses said to the people, Let men from among you be armed for war to put into effect against Midian the Lord's punishment on them.

4 From every tribe of Israel send a thousand to the war.

5 So from the thousands of Israel a thousand were taken from every tribe, twelve thousand men armed for war.

6 And Moses sent them out to war, a thousand from every tribe, and with them Phinehas, the son of Eleazar the priest, taking in his hands the vessels of the holy place and the horns for sounding the note of war.

7 And they made war on Midian, as the Lord gave orders to Moses; and they put to death every male.

8 They put the kings of Midian to death with the rest, Evi and Reken and Zur and Hur and Reba, the five kings of Midian: and Balaam, the son of Beor, they put to death with the sword.