http://revach.net/article.php?id=3011

Section: Parshas HaShavua   Category: Quick Vort
Parshas Chayei Sara: Ba'al HaTurim - Eisav's Naughty Uncle Lavan

"UliRivka Ach Ushmo Lavan; And Rivka had a brother whose name was Lavan."  The Baal HaTurim points out that we find the word "UliRivka" in another place in the Torah - "Vatiyena Moras Ruach LiYitzchok UliRivka; Eisav's wives were a rebellious spirit to Yitzchok and Rivka." 

The Baal HaTurim explains the connection between these 2 psukim. The Gemara says that most sons turn out similar to their mother's brother. If you want to know why Esav was so evil and, "Vatiyena Moras Ruach LiYitzchok UliRivka,"  it was because, "UliRivka Ach Ushmo Lavan." Esav was similar to his mother's brother - Uncle Lavan!