C. F. Keil and Franz Delitzsch on Genesis 47:20-21

Gen 47:20-21

Thus Joseph secured the possession of the whole land to Pharaoh by purchase, and “the people he removed to cities, from one end of the land of Egypt to the other.” לערים, not from one city to another, but “according to (= κατά) the cities;” so that he distributed the population of the whole land according to the cities in which the corn was housed, placing them partly in the cities themselves, and partly in the immediate neighbourhood.