Sforno on Deuteronomy 32:8/ספורנו על דברים ל״ב:ח׳

1יצב גבולות עמים, after the tower of Babylon episode, when mankind had lived in a single community, G’d separated them, dividing them up, and established territorial boundaries for the various new nations. Instead of destroying the people who had engaged in building the tower as a challenge to G’d, He did not destroy them as He had the generation of the deluge, but limited their future scope of influence, by assigning only clearly marked territories within which they could be sovereign.

2למספר בני ישראל. For the sake of the Children of Israel who were few in numbers, and who would eventually emerge from among these nations. Proof of all this is כי חלק ה' עמו, that G’d has no special claim on any nation other than the people of Israel. All the other nations worship alien deities. Moses explains that had it not been for the fact that G’d knew that the people of Israel would emerge eventually from among one of these nations, He would have wiped out all the people involved in the building of the tower.