4-6. Speak not thou in thine heart, . . . saying, For my righteousness the Lord hath brought me in to possess this land—Moses takes special care to guard his countrymen against the vanity of supposing that their own merits had procured them the distinguished privilege. The Canaanites were a hopelessly corrupt race, and deserved extermination; but history relates many remarkable instances in which God punished corrupt and guilty nations by the instrumentality of other people as bad as themselves. It was not for the sake of the Israelites, but for His own sake, for the promise made to their pious ancestors, and in furtherance of high and comprehensive purposes of good to the world, that God was about to give them a grant of Canaan.