Deuteronomy 20:10-20
The children of Israel were authorised to make peace with distant towns. In contrast there was to be no mercy for the cities nearby, those which were preventing the people from possessing the land. As far as we are concerned as Christians, we have a distinction to make regarding things of the earth, between those which we can legitimately make use of and those which we should resolutely reject because they would deprive us of the enjoyment of our heavenly inheritance. It is up to us to distinguish between them.
The Israelite had to respect the fruit trees and not use them for war. Here is a warning which can have a spiritual meaning! One sees some Christians showing a blind and sectarian zeal, condemning and brandishing as a weapon of war something which after all God has perhaps given to refresh and feed His own. These vv. 19 and 20 warn us at the same time against wastage. Let us think of the example which Jesus Himself gave us. He, the Creator who could infinitely multiply the loaves of bread — and had just proved it — was careful to have all the remains gathered up in baskets "that nothing be lost" (John 6:12).