Moses
Numbers 31:17ESV·traditional attribution

Now therefore, kill every male among the little ones, and kill every woman who has known man by lying with him.

John Gill Reformed Baptist @doctorgill

And do ye abide without the camp seven days..... Which was the time that anyone that touched a dead body remained unclean, Num 19:11, whosoever hath killed any person; as most of them if not all must have done; all the males of Midian that fell into their hands being slain by them, that were men grown: and whosoever hath touched any slain; as they...

Geneva Bible Notes Reformed @genevanotes

Now therefore kill every male among the little ones, and kill every woman that hath known man by lying with him. (g) That is, all the boy children.

Keil & Delitzsch Lutheran @keilanddelitzsch

Num 31:13-18 Treatment of the Prisoners. - When Moses went out to the front of the camp with Eleazar and the princes of the congregation to meet the returning warriors, he was angry with the commanders, because they had left all the women alive, since it was they who had been the cause, at Balaam’s instigation, of the falling away of the Israelites from Jehovah...

Commenting on Numbers 31:13-18