For the Lord has driven out from before you, etc He intimates that so long as they do not themselves change, there will certainly be no change on the part of God. Therefore he asserts that, provided they conciliate the favor of God, they shall have an uninterrupted course of victory. At length he again exhorts them, as they value their life and safety, to be careful in maintaining love to God. From this source all true obedience springs; for if we do not cling to him with free and ardent affection, we shall study in vain to frame our lives in accordance with the external form of the Law.

For the Lord hath driven out before you great nations and strong,.... Especially as they were reckoned in those times, before any great monarchies had existed, as did afterwards; and indeed these were, considering the land they inhabited, very numerous and populous, and were very stout and able bodied men, and some of a gigantic stature; and all dwelt in strong fortified cities, and were able to bring out large armies into the field, with chariots of iron, so that they were very formidable; but notwithstanding all this, the Lord drove them out of their strong holds, and put Israel into the possession of them, and of their land:
but as for you, no man hath been able to stand before you unto this day; that is, of those that came out against them, and fought with them; these were all to a man cut off by them, or fled before them, and became tributaries to them; otherwise there were many, who as yet were not expelled by them; this the Lord had promised, and now had fulfilled, Deuteronomy 11:25.

No man - To wit, whom you have invaded; otherwise some of those people did yet remain unconquered.