John Gill's Exposition of the Whole Bible
Numbers 31:7
And they warred against the Midianites, as the Lord commanded Moses,.... Whether the Midianites came out against them with an army, and there was a pitched battle between them, is not certain; however the Israelites committed acts of hostility upon them, by entering their cities, plundering their houses, and slaying the inhabitants of them; the Targum of Jonathan is,
"they warred against Midian, and surrounded it in the three corners of it, as the Lord commanded Moses;''
for, as Maimonides b observes from tradition,
"when they besiege a city to take it, they do not surround it in the four corners of it, but in the three corners of it, and leave a place to flee out, that everyone that would might escape for his life, as it is said, "and they warred against Midian, as the Lord commanded Moses"; by report, or from tradition, it is learnt that so he commanded him;''
that is, in such a manner to besiege a city; but for this there is only tradition, for it is not mentioned among the rules after directed to in such a case, Deuteronomy 20:10,
and they slew all the males; which fell into their hands; for, no doubt, there were multitudes that made their escape, since in later times we read of the Midianites, as a very powerful people, and very distressing to Israel, Judges 6:1 these, as Aben Ezra observes, they slew, were such as were grown up, for as for their little ones, them they spared and carried captive, Numbers 31:9.
b Hilchot Melacim, c. 6. sect. 7.