2 Chronicles 20:10

And now, behold, the children of Ammon, and Moab, and Mount Seir, whom thou wouldest not let Israel invade, when they came out of the land of Egypt,.... Charging them not to meddle with them, nor take any of their lands from them, Deuteronomy 2:5,

but they turned from them, and destroyed them not; in obedience to the divine command, when it was in their power to have done it.