Genesis 28:6-9

Now Esau noticed that Isaac had blessed Jacob and sent him to Paddan-aram to take a wife for himself from there, and that as he blessed him he gave him a prohibition, saying, “You shall not take a wife from the daughters of Canaan,” and that Jacob obeyed his father and his mother and had gone to Paddan-aram. So Esau realized that [his two wives] the daughters of Canaan displeased Isaac his father; and [to appease his parents] Esau went to [the family of] Ishmael and took as his wife, in addition to the wives he [already] had, Mahalath the daughter of Ishmael, Abraham’s son, the sister of Nebaioth [Ishmael’s firstborn son].