Deuteronomy 2:9

9.And the Lord said unto me, Distress not the Moabites. He had previously forbidden them to enter the land of Edom, unless consent were obtained. A similar prohibition is now added with respect to the Moabites, because God had allotted to them the territory which they inhabited. As I have said, this was painful and burdensome, that they should cherish kindness and fraternal good-will towards those who treated them with hostility; but God desired in this respect also to prove the obedience of His people. He did not, then, take into consideration what this nation had dcserved; but, inasmuch as they were the descendants of Lot, and consequently of the race of Abraham, He desired to treat them with special favor. For the division of the whole world appertains to Him, so as to distribute to its various peoples whatever part He chooses, and to fix the bounds wherein they should confine themselves. If any object that the people of Canaan had also their limits assigned to them, and ought not, therefore, to have been expelled from the lands in which their forefathers had for many ages inhabited, the reply is easy, viz., that God is always free to take away what He has given, and to readjust the boundaries imposed by His will, when the sins of men deserve that this should be done. When, therefore, He declares that He had given their land to the Moabites, it is not according to the ordinary force of the expression, but by a fixed decree that their habitation should remain sure and undisturbed.