Numbers 31:7-17

7And they warred against Midian, as Jehovah commanded Moses; and they slew every male. 8And they slew the kings of Midian with the rest of their slain: Evi, and Rekem, and Zur, and Hur, and Reba, the five kings of Midian: Balaam also the son of Beor they slew with the sword. 9And the children of Israel took captive the women of Midian and their little ones; and all their cattle, and all their flocks, and all their goods, they took for a prey. 10And all their cities in the places wherein they dwelt, and all their encampments, they burnt with fire. 11And they took all the spoil, and all the prey, both of man and of beast. 12And they brought the captives, and the prey, and the spoil, unto Moses, and unto Eleazar the priest, and unto the congregation of the children of Israel, unto the camp at the plains of Moab, which are by the Jordan at Jericho.

13And Moses, and Eleazar the priest, and all the princes of the congregation, went forth to meet them without the camp. 14And Moses was wroth with the officers of the host, the captains of thousands and the captains of hundreds, who came from the service of the war. 15And Moses said unto them, Have ye saved all the women alive? 16Behold, these caused the children of Israel, through the counsel of Balaam, to commit trespass against Jehovah in the matter of Peor, and so the plague was among the congregation of Jehovah. 17Now therefore kill every male among the little ones, and kill every woman that hath known man by lying with him.