Numbers 31:15

15 And Moses said to them, Why have ye saved every female alive?

Numbers 31:15 In-Context

13 And Moses and Eleazar the priest and all the rulers of the synagogue went forth out of the camp to meet them.
14 And Moses was angry with the captains of the host, the heads of thousands and the heads of hundreds who came from the battle-array.
15 And Moses said to them, Why have ye saved every female alive?
16 For they were to the children of Israel by the word of Balaam of their revolting and despising the word of the Lord, because of Phogor; and there was a plague in the congregation of the Lord.
17 Now then slay every male in all the spoil, slay every woman, who has known the lying with man.

The Brenton translation of the Septuagint is in the public domain.