Sforno on Deuteronomy 4:32/ספורנו על דברים ד׳:ל״ב

1כי שאל נא, the proof of what I said that G’d will not forget the covenant made with your forefathers is that at Mount Sinai during the revelation all of you had been elevated to the level of prophecy. When I took you to be My people this did not mean that each and everyone of you by their own merits had deserved to be elevated to that spiritual status. I did this on account of the patriarchs. The difference between you and the gentile nations is that although the exceptional gentile may have experienced prophetic insights, there never has been a nation who have experienced something similar as a whole nation as you did at Mount Sinai.