The Lord used Israel to punish the Canaanites and other peoples in the land, which meant that Israel would remove the people completely through warfare. However, Israel would then live in the land and so Israel had to be careful not to destroy the land completely,

“When you besiege a city for a long time, while making war against it to take it, you shall not destroy its trees by wielding an ax against them; if you can eat of them, do not cut them down to use in the siege, for the tree of the field is man’s food. Only the trees which you know are not trees for food you may destroy and cut down, to build siegeworks against the city that makes war with you, until it is subdued” (Deuteronomy 20:19–20).

Israel would need food, and so the Lord taught them to be careful that they not hurt their own food supply. Sometimes people hurt their own neighborhoods through graffiti and other crime, and wonder why they cannot get jobs later. Therefore, let us learn to take care of the places where we live, for it will only help us in the long run.