Joseph took some from among his brethren, and presented them to Pharaoh. He chose the weakest of them, that the king might not be tempted to retain them in his service as warriors. And as he did not desire his family to live at close quarters with the Egyptians and perhaps amalgamate with them, he introduced them as shepherds. The Egyptians worshipped the constellation of the rain, and paid divine honors to animals, and they kept aloof from shepherds. Pharaoh therefore was inclined to grant Joseph's wish, to give them the pasture land of Goshen for their sojourning place, the land that was theirs by right, for the Pharaoh that took Sarah away from Abraham by force had given it to her as her irrevocable possession.
Pharaoh — Joseph Among the Fathers
Legends of the Jews 1:340