Rashi comments: And Unkelus translates ben zekunim as “he was a wise son to him” – whatever Yaakov learned from Shem and Ever he transmitted to Yosef.
The commentary indicates that the source of the brothers’ jealousy of Yosef was that their father had transmitted to him the Torah he had studied at the Yeshiva of Shem and Eiver. They reasoned that just as with Avrohom and Yitzchok only one son was worthy of receiving the tradition from his father, so too, Yosef would be that one. The brothers then asked, “Why doesn’t our father also teach us the Torah he had studied in the Yeshiva of Shem and Ever?”
Are there two Torahs, the Torah of the Patriarchs which Yaakov studied with his sons, and the Torah of Shem and Ever which he only studied with Yosef? Obviously, there is only one Torah, but at times there are different areas of emphasis in teaching the Torah. Our Chazal tell us, the Patriarchs established houses of study for themselves and others wherever they were. They taught that we must always reach out to everyone by learning and teaching the Torah and spreading its light to the world. This was the essence of the Torah of our Patriarchs.
Shem and Ever did not have the wonderful opportunities for study and teaching which the Patriarchs had. Shem who lived during the era of the Great Flood, and Eiver who lived during the Generation of the Tower of Bavel, were exposed to a society completely opposed to Torah values. The goals and objectives of their teachings were to stress the evil effects of the society in which they lived and how to protect themselves from its influence.
Their teachings served as a beacon of light for Yaakov as he embarked on his journey to Charan. He was now prepared for the many years he would spend in the presence of Lavan. These special teachings were those which Yaakov transmitted to Yosef to prepare him to live most of his life away from his family in a land alien to Torah values. The brothers however, not being aware of Yosef’s future, mistakenly were jealous of him.
