There are much more learned people than I but as a student of history I wanted to share this. In Surah Yusuf, the ruler of Egypt is described as “King” or Malik. In every other reference to the ruler of Egypt, the word “Pharoah” is used, latinized Firaun.
43. “And (once) the king (of Egypt) said: ‘Verily I saw (in a dream) seven fat cows which seven lean cows were eating; and seven green ears of corn and other (seven) dry. O’ chiefs (of my court)! Explain to me my dream, if you are able to interpret dreams’.”
49. And [recall] when We saved your forefathers from the people of Pharaoh, who afflicted you with the worst torment, slaughtering your [newborn] sons and keeping your females alive. And in that was a great trial from your Lord.
It is historical fact that the Hyksos Kings, a Canaanite people ruled over Egypt for a brief period from 1650-1550 BC, the first red line on the left, when it is estimated Prophet Yusuf AS was enduring there.
How would an unlettered man in Arabia have known this detail, our Prophet Muhammed peace be upon him.