When the most High divided to the nations their inheritance, when he separated the sons of Adam, he set the bounds of the people according to the number of the children of Israel. When the Most High divided to the nations, etc. - Deuteronomy 32:8 and Deuteronomy 32:9, says Dr. Kennicott, give us express authority for believing that the earth was very early divided in consequence of a Divine command, and probably by lot, (see Acts 17:26); and as Africa is called the land of Ham, (Psalms 78:51; Psalms 105:23, Psalms 105:27; Psalms 106:22), probably that country fell to him and to his descendants, at the same time that Europe fell to Japheth, and Asia to Shem, with a particular reserve of Palestine to be the Lord's portion, for some one peculiar people. And this separation of mankind into three bodies, called the general migration, was commanded to Noah, and by him to his sons, so as to take place in the days of Peleg, about two hundred years afterwards. This general migration was prior to the partial dispersion from Babel by about five hundred years.
He set the bounds of the people according to the number of the children of Israel - The Septuagint is very curious, Εστησεν ὁρια εθνων κατα αριθμον αγγελων του Θεου. "He established the bounds of the nations according to the number of the angels of God." The meaning of the passage seems to be, that when God divided the earth among mankind, he reserved twelve lots, according to the number of the sons of Jacob, which he was now about to give to their descendants, according to his promise.