When the Most High divided the nations: when he separated the sons of Adam, he appointed the bounds of people according to the number of the children of Israel.

“Moses represents God as descending to the tower that the sons of men were building, seeking to inspect it and saying, "Come, let us go down quickly, and there confuse their language, so that they may not understand one another's speech." Who do the heretics think was the God that descended to the tower in this passage and then sought to visit these men? Was he God the Father? In that case, God is enclosed in a place. If so, how then does he embrace all things? Or is it possible that he speaks of an angel descending with other angels and saying, "Come, let us go down quickly, and there confuse their language"? On the contrary, we note in Deuteronomy that it was God who recounted these things and God who spoke, where it is written: "When he scattered abroad the sons of Adam, he set up the boundaries of the people according to the number of the angels of God." Therefore the Father did not descend, nor did an angel command these things, as the narrative clearly indicates. Accordingly, the only remaining conclusion is that he descended of whom the apostle Paul says, "He who descended, he it is who ascended also above all heavens, that he might fill all things," that is, the Son of God, the Word of God.”

“בהנחל עליון גוים WHEN THE MOST HIGH DIVIDED TO THE NATIONS THEIR INHERITANCE — when the Holy One, blessed be He gave those who provoked Him to anger their inheritance, He afterwards caused the flood to pass over them and He drowned them (Sifrei Devarim 311:1) בהפרידו בני אדם WHEN HE SEPARATED THE SONS OF ADAM — i.e. when He scattered the generation which witnessed the separation of races, He also had the power to remove them from the world, yet He did not do so, but יצב גבלת עמים HE FIRMLY ESTABLISHED THE BOUNDARIES OF THE NATIONS — He let them (the peoples) remain in existence and did not destroy them, למספר בני ישראל ACCORDING TO THE NUMBER OF THE CHILDREN OF ISRAEL — i.e. because of the number of the children of Israel that were in future to descend from Shem’s sons, and in accordance with the number of seventy souls of the children of Israel who went down to Egypt He firmly established גבלת עמים THE NATIONS ACCORDING TO THEIR BOUNDARIES — i.e. seventy separate nations (cf. Sifrei Devarim 311:5).”

“When the Most High divided to the nations their inheritance,.... In the times of Noah and his sons, in the days of Peleg, who had his name (that is "Division") from thence, Gen 10:25; "the Most High" is a well known and proper, epithet of God; the dividing of the earth to the several nations of it, and giving to everyone their part and portion to possess and inherit, was the work of God; for though it was done by the sons of Noah, yet by the order, appointment, and direction of the Most High, who rules in heaven and in earth, Gen 10:32; men might not and did not take what they pleased, or seize on as much as they could, but each had their parcel allotted and portioned out to them, by the Lord himself; so the Targum of Jonathan."when by lot the Most High divided the world to the people that sprung from the sons of Noah:" when he separated the sons of Adam; one from another; distinguished by the persons from whom they descended, by the tribes and nations to which they belonged, and by the countries they inhabited; for though they descended from Noah and his sons, they were the sons of Adam, the first man: or rather "the children of men", as the wicked of that generation were called, in distinction from the sons of God, or his people and worshippers; and may have respect to the separation of them at Babel, where their languages were confounded, and they were scattered about, and some went into one part of the world, and some into another, according to the appointment and direction of divine Providence; so the builders of Babel are called, and this was what befell them, Gen 11:5; which sense the above Targum confirms,"when he separated the writings, the languages of the children of men in the generation of the division:'' he set the bounds of the people; or nations, the seven nations of the land of Canaan; he pitched upon and fixed the land they should inherit, and settled the bounds of it, how far it should reach, east, west, north and south: according to the number of the children of Israel: the sense is, that such a country was measured out and bounded, as would be sufficient to hold the twelve tribes of Israel, when numerous, and their time was come to inhabit it; and which, in the mean while was put into the hands of Canaan and his eleven sons to possess; not as their proper inheritance, but as tenants at will, until the proper heirs existed, and were at an age, and of a sufficient number to inherit; in which may be observed the wise disposition of divine Providence, to put it into the hands of a people cursed of God, so that to take it from them at any time could not have the appearance of any injustice in it; and their enjoying it so long as they did was a mercy to them, for so long they had a reprieve: now here was an early instance of the goodness of God to Israel, that he should make such an early provision of the land flowing with milk and honey for them, even before they were in being, yea, before their ancestors, Abraham, Isaac, and Jacob, existed; as early as the days of Noah; and yet, ungrateful as they were despised and set at nought his Son, the rock of salvation, when sent unto them: thus the heavenly inheritance, typified by the land of Canaan, was not only promised, but prepared, provided, secured, and reserved for the spiritual Israel of God, before the foundation of the world, from all eternity, and which is appointed according to their number; there is room enough in it for them all, though they are many; in it are many mansions for the many sons to be brought to glory.”

“Israel. He suffered the people of Chanaan to occupy as much land as would be requisite for the Israelites. Septuagint, “according to the number of the angels of God.” Hence many of the ancients gathered that there were seventy angel guardians of provinces, and as many languages; while others did not pretend to determine the exact number. But the version which they have followed, is in opposition to all the rest. (Calmet) — They have also disputed on this occasion, whether the elect will be equal in number to the good angels, as St. Gregory thinks; (hom. 34, in Luke xv.) or they will only fill up the places of those who have fallen. See Mag. Sent. ii. 9. Abenezra observes, that interpreters understand this text as alluding to the dispersion of nations, (Genesis xi.) when God decreed that the land of the seven nations should belong to and be sufficient for the Israelites. (Amama) (Haydock) — The Hebrew may be rendered, “He fixed the limits of each people. At that time the children of Israel were few in number, ( 9 ) when the Lord chose his people,” &c. Long after the division of the earth, (which the Lord had ordered, Acts xvii. 26,) the Israelites were very few in number, as Jacob observes, Genesis xxxiv. 30. See chap. xxvi. 5., and Psalm civ. 9, 12. (Calmet) — But this explication does not satisfy Houbigant, (p. 76, Prol.) no more than that of Le Clerc. He is convinced that a word has been transposed, and another left out, as the Samaritan copy has Israel twice, and he would therefore translate, “He divided his people according to the number of the sons of Israel.” In his eternal decrees, He allotted twelve portions of land in Chanaan to the descendants of Jacob, and these Josue was ordered to mark out for them. See Josue iv. 5. (Haydock)”

“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 (Gen 10:5; Deu 2:5-9; Act 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 Deu 30:5; Gen 34:30; Psa 105:9-12).”