Комментарий к Берешит 9:19

שלשה אלה בני נח, seeing that all of them were Noach’s sons, G’d blessed them all, even though one of them was wicked, when He said “be fruitful and multiply and fill the globe.” As a result of this blessing, באלה נפצה כל הארץ, the entire population of the earth traces its origin to one of these three sons of Noach.

שלשה...נפצה, the root of the word is נפץ, an intransitive verb appearing also in Samuel I 13,11 כי נפץ העם מעלי, “the people were leaving me.” The word is used in this sense also in respect of the people dispersing over the earth on the occasion of the tower of Babylon and its collapse.

From these the whole world developed. Hashem intended humankind to be comprised of three categories: 1) simple workers, 2) refined intellectuals and 3) people of God who would serve as His “throne” on earth.