Matthew Henry on Joshua 12

Fresh mercies must not drown the remembrance of former mercies, nor must the glory of the present instruments of good to the church diminish the just honour of those who went before them, since God is the same who wrought by both. Moses gave to one part of Israel a very rich and fruitful country, but it was on the outside of Jordan. Joshua gave to all Israel the holy land, within Jordan. So the law has given to some few of God's spiritual Israel worldly blessings, earnests of good things to come; but our Lord Jesus, the true Joshua, provided for all the children of promise spiritual blessings, and the heavenly Canaan.

We have here the limits of the country Joshua conquered. A list is given of the kings subdued by Israel: thirty-one in all. This shows how fruitful Canaan then was, in which so many chose to throng together. This was the land God appointed for Israel; yet in our day it is one of the most barren and unprofitable countries in the world. Such is the effect of the curse it lies under, since its possessors rejected Christ and his gospel, as was foretold by Moses, De 29:23. The vengeance of a righteous God, inflicted on all these kings and their subjects, for their wickedness, should make us dread and hate sin. The fruitful land bestowed on his chosen people, should fill our hearts with hope and confidence in his mercy, and with humble gratitude.