fom: http://www.thebricktestament.com
When Esau was forty years old he married Judith daughter of Beeri the Hittite, and Basemeth daghter of Elon the Hittite.
These were a bitter disappointment to Isaac and Rebekah. Rebekah said to Isaac, The Hittite women sicken me to death. If Jacob were to marry a Hittite woman like these, what would there be left in life for me
So Isaac summoned Jacob; and he gave him this order: You are not to marry any of the Canaanite women. Go off to Padan-Aram, the home of Bethuel your mothers father, and there choose a wife for yourself from the daughters of Laban your mothers brother.
When Esau saw that Isaac had blessed Jacob and sent him to Padan-Aram to choose a wife there, Esau then realized how much his father Isaac disapproved of the Canaanite women.