In Bresheit 34:1-2 "Now Dinah the daughter of Leah, whom she had born to Yakov, went out to see the daughters of the land. And when Shechem the son of Hamor the Hivite, prince of the country saw her, he took her and lay with her, and violated her."
Bresheit 41:45 " ...and he (Pharaoh)gave him (Yosef)as a wife Asenath, the daughter of Poti-Pherah priest of On..."
I was taught that there is a commentary which states that Asenath was the illegitimate daughter of Dinah when she was violated in Shechem.
Poti-Pherah was emasculated and unable to produce offspring, so he took Dinah as a daughter who happened to be with child (Asenath).
Can anyone verify this and cite the commentary where this can be found?