An obvious question that we must ask in analyzing this week's Parsha emerges from the Posuk which says that Yaakov loved Yosef more than any of his other children, and made him a coat of many colors (בראשית ל"ז:ג'). How could such a great man as Yaakov show open favoritism to one of his sons in a fashion that would undoubtedly create jealousy?
Looking back at all the Avos, we see a certain pattern. Each one of the Avos had at least two sons on whom to bestow Berachos. In all cases, they were initially unsure as to which son to pick to be the chosen one. In Avraham's case, Avraham had to make a choice between his oldest son Yishmael, and Yitzchak, the "Bechor" from his favorite wife, Sarah. Avraham is persuaded by Sarah as to which child to choose; by choosing Yitzchak, Avraham is forced to totally disregard Yishmael. In Yitzchak's case, he is forced to choose between two real Bechoros, from the same mother; the two twins Eisav and Yaakov were born at virtually the same time, and Yitzchak thus had a dilemma as to which one to pick. He too is influenced by his wife as to which son to pick; by picking Yaakov, Yitzchak is forced to throw Eisav out of the Jewish lineage forever.
Yaakov, however, has the toughest decision to make. His favorite wife has died so he has no one
to help him out with his decision, and Yaakov is somewhat inconclusive. He finally does pick Yosef, Rochel's "Bechor," to be his chosen son. This is shown by the coat he gives Yosef which puts him on a higher level than his brothers. It is also shown later before Yaakov dies, when he gives Yosef two portions, one for Menasheh and one for Ephraim; it is generally the right of the Bechor to get two portions. But the reason Yaakov's choice is so much more devastating than that of the other Avos is that really all of the brothers end up as Bechoros in a certain sense, because none of them are totally rejected. Thus when Yaakov shows favoritism to one of his children, without throwing the rest out like the other Avos did, he creates tremendous animosity, because the distinction between them is somewhat blurred, since all the children remain part of the Jewish fold, and as Sefer Bereishis progresses, another son, Yehudah, actually develops as the recognized leader.
In reality, this question as to who is Yaakov's true Bechor has never been resolved. After Shlomo HaMelech's reign, the nation split into two sections, the kingdom of Yehudah and the kingdom of Yisrael. Many kings of Yisrael were from either Menasheh or Ephraim, and indeed, the kingdom was often called the kingdom of Ephraim; as we know, the two kingdoms of Yehudah and Yisrael did not always get along very well. This animosity between Yehudah and Yosef will not end until the time of Moshiach, when there will first be a Moshiach Ben Yosef, who will be killed, and then there will be a Moshiach Ben Dovid, who will represent the total rule by Yehudah, who interestingly was not the Bechor that Yaakov initially picked. Once this is accomplished, Bnai Yisrael will finally be one nation, never to be divided again.