John Gills Exposition of the Bible Commentary - Deuteronomy 20:20
Only the trees which thou knowest that they be not trees for meat,.... Which might be known not only by their not having fruit upon them, but by other tokens, and even at a time of year when there was no fruit on any, which might be sometimes the season of a siege: thou shalt destroy and cut them down ; if so to do was of any disservice to the enemy, or of any service to them, as follows; they had a liberty to destroy them if they would: and thou shall build bulwarks against the city... read more
Matthew Henry's Complete Commentary - Deuteronomy 20:10-20
They are here directed what method to take in dealing with the cities (these only are mentioned, Deut. 20:10; but doubtless the armies in the field, and the nations they had occasion to deal with, are likewise intended) upon which they made war. They must not make a descent upon any of their neighbours till they had first given them fair notice, by a public manifesto, or remonstrance, stating the ground of their quarrel with them. In dealing with the worst of enemies, the laws of justice and... read more