And when the Lord thy God hath delivered it into thine hands,.... When, what with pressures without, and calamities within, the city is obliged to surrender: this is not to be imputed to the methods and arts of war used in besieging, or to the courage and skill of the besiegers; but to the power and providence of God succeeding means used, and sending famine or pestilence among the besieged, and inclining their hearts to deliver up their city:

thou shall smite every male thereof with the edge of the sword; the men in it, grown persons, as distinguished from little ones in the next verse; because it was owing to these it was not surrendered at once, when terms of peace were offered.

And when the LORD thy God hath delivered it into thine hands, thou shalt smite every male thereof with the edge of the sword:

20:10-12 The Israelites are here directed about the nations on whom they made war. Let this show God's grace in dealing with sinners. He proclaims peace, and beseeches them to be reconciled. Let it also show us our duty in dealing with our brethren. Whoever are for war, we must be for peace. Of the cities given to Israel, none of their inhabitants must be left. Since it could not be expected that they should be cured of their idolatry, they would hurt Israel. These regulations are not the rules of our conduct, but Christ's law of love. The horrors of war must fill the feeling heart with anguish upon every recollection; and are proofs of the wickedness of man, the power of Satan, and the just vengeance of God, who thus scourges a guilty world. But how dreadful their case who are engaged in unequal conflict with their Maker, who will not submit to render him the easy tribute of worship and praise! Certain ruin awaits them. Let neither the number nor the power of the enemies of our souls dismay us; nor let even our own weakness cause us to tremble or to faint. The Lord will save us; but in this war let none engage whose hearts are fond of the world, or afraid of the cross and the conflict. Care is here taken that in besieging cities the fruit-trees should not be destroyed. God is a better friend to man than he is to himself; and God's law consults our interests and comforts; while our own appetites and passions, which we indulge, are enemies to our welfare. Many of the Divine precepts restrain us from destroying that which is for our life and food. The Jews understand this as forbidding all wilful waste upon any account whatsoever. Every creature of God is good; as nothing is to be refused, so nothing is to be abused. We may live to want what we carelessly waste.