Jamieson, Fausset and Brown on Deuteronomy 32:8-9

8-9. When the most High divided to the nations their inheritance--In the division of the earth, which Noah is believed to have made by divine direction (Ge 10:5; De 2:5-9; Ac 17:26, 27), Palestine was reserved by the wisdom and goodness of Heaven for the possession of His peculiar people and the display of the most stupendous wonders. The theater was small, but admirably suited for the convenient observation of the human race--at the junction of the two great continents of Asia and Africa, and almost within sight of Europe. From this spot as from a common center the report of God's wonderful works, the glad tidings of salvation through the obedience and sufferings of His own eternal Son, might be rapidly and easily wafted to every part of the globe.

he set the bounds of the people according to the number of the children of Israel--Another rendering, which has received the sanction of eminent scholars, has been proposed as follows: "When the Most High divided to the nations their inheritance, when He separated the sons of Adam and set the bounds of every people, the children of Israel were few in numbers, when the Lord chose that people and made Jacob His inheritance" (compare De 30:5; Ge 34:30; Psa 105:9-12).