Charles Ellicott Commentary Numbers 31:15

"And Moses said unto them, Have ye saved all the women alive?" — Numbers 31:15 (ASV)

Have you saved all the women alive?— It was the women, as is expressed in the following verse, who had been the cause, at the instigation of Balaam, of the apostasy of the Israelites; and consequently the command to avenge the Lord of Midian implied the punishment of those who had been the instruments employed in the seduction of the Israelites.