Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

Upon this report the people as a whole, of course through their rulers, were to examine closely into the affair (היטב, an adverb, as in Deu 9:21), whether the word was established as truth, i.e., the thing was founded in truth (cf. Deu 17:4; Deu 22:20); and if it really were so, they were to smite the inhabitants of that town with the edge of the sword (cf. Gen 34:26), putting the town and all that was in it under the ban. "All that is in it" relates to men, cattle, and the material property of the town, and not to men alone (Schultz). The clause from "destroying" to "therein" is a more minute definition of the punishment introduced as a parenthesis; for "the cattle thereof," which follows, is also governed by "thou shalt smite." The ban was to be executed in all its severity as upon an idolatrous city: man and beast were to be put to death without reserves; and its booty, i.e., whatever was to be found in it as booty-all material goods, therefore - were to be heaped together in the market, and burned along with the city itself. ליהוה כּליל (Eng. Ver. "every whit, for the Lord thy God") signifies "as a whole offering for the Lord" (see Lev 6:15-16), i.e., it was to be sanctified to Him entirely by being destroyed. The town was to continue an eternal hill (or heap of ruins), never to be built up again.