Deuteronomy 20:10-20 -

Directions concerning the besieging of towns . In the case of a town at a distance, not belonging to any of the Canaanitish tribes, on advancing against it they were first of all to summon the inhabitants to a peaceable surrender and submission (cf. 21:13 ). If this was complied with, the inhabitants were to become tributary to the Israelites and serve them; but if this was refused, the town was to be besieged, and, when taken, all the males were to be slain, and the women and children, as well as all the booty that was in the place, were to be taken as the prey of the conquerors, who were to appropriate the spoil to their own use.