Chasidut zu Schemot 1:6

Exodus 1,6. “and Joseph had meanwhile been in Egypt ‎already.” We need to examine why the Torah had to repeat ‎the word ‎במצרים‎, “in Egypt,” when it would have sufficed to ‎simply write ‎ויוסף היה שם‎, “while Joseph had already been there.” ‎Perhaps the Torah wanted to stress that during all the years that ‎Joseph had been in Egypt without the moral support of his family ‎he had not changed his name (although Pharaoh had given him ‎an Egyptian title, i.e. ‎צפנת פענח‎). He himself used to refer to ‎himself by his Jewish name. Even Pharaoh realized this when ‎during the early days of the famine he had instructed the people ‎to turn to Joseph for help, i.e. ‎לכו אל יוסף אשר יאמר לכם תעשו‎, ‎‎“what Joseph will tell you, you are to do.” (Compare Bereshit ‎Rabbah 20 slightly differently wording.)‎