Genesis 28:1-2, 8

Before Jacob left, Isaac called for him, blessed him, and gave him these instructions: “I forbid you to marry any Canaanite woman. Leave at once for the land of your grandfather Bethuel in Paddan-Aram and find one of the young women there to marry, one of your uncle Laban’s daughters.

Esau, knowing that his father Isaac disapproved of Canaanite women