Adam Clarke on Genesis 45:8

He hath made me a father to Pharaoh - It has already been conjectured that father was a name of office in Egypt, and that father of Pharaoh might among them signify the same as prime minister or the king's minister does among us. Calmet has remarked that among the Phoenicians, Persians, Arabians, and Romans, the title of father was given to certain officers of state. The Roman emperors gave the name of father to the prefects of the Praetorium, as appears by the letters of Constantine to Ablavius. The caliphs gave the same name to their prime ministers. In Jdg 17:10, Micah says to the young Levite, Dwell with me, and be unto me a Father and a priest. And Diodorus Siculus remarks that the teachers and counsellors of the kings of Egypt were chosen out of the priesthood.