C. F. Keil and Franz Delitzsch on Deuteronomy 13:17

Deu 13:17

To enforce this command still more strongly, it is expressly stated, that of all that was burned, nothing whatever was to cleave or remain hanging to the hand of Israel, that the Lord might turn from His wrath and have compassion upon the nation, i.e., not punish the sin of one town upon the nation as a whole, but have mercy upon it and multiply it, - make up the diminution consequent upon the destruction of the inhabitants of that town, and so fulfil the promise given to the fathers of the multiplication of their seed.