In this week's Parsha, we are told that Yaakov Avinu, before his death, blesses his grandchildren, the sons of Yosef. Yaakov is the central figure in this Parsha, as he is throughout all the Parshiyos in Sefer Bereishis since his birth is described in Parshas Toldos. Once Yaakov is born, the other Avos, Avraham and Yitzchak, are basically ignored, despite the fact that for at least part of the time, they are still alive. For example, we know that Avraham was still alive up until the time when Eisav sold Yaakov the birthright, but after the death of Soroh, the Torah devotes no attention to him, as if he too had already died. Likewise, Chazal tell us that Yitzchak knew about Yosef being sold into slavery by his brothers, but the Torah says nothing about him. Once Yaakov comes onto the scene, we hear only about him and his family, not about the other Avos. Why does Yaakov "take over" and get so much attention while the other great Avos are basically written out of the story?
HaRav Joseph B. Soloveitchik once explained the greatness of Yaakov as going beyond that of the other Avos for an important reason. Yaakov is sometimes referred to by Chazal as ישראל סבא, Yisrael the Grandfather. Yaakov was, in a way, the first Jewish grandfather, because he was the first to have a relationship not only with all his children, but with his grandchildren as well. Avraham and Yitzchak are not dealt with in the Torah once the next generation arrives because they had no input or relationship with that generation. Once their own sons had children of their own, they dropped out of the picture. Yaakov, however, did establish a relationship with his grandchildren; he thus remains the central figure even when the new generation arrives. Rav Soloveitchik added that the survival of the Jewish people depends on the bond established between fathers, sons, and grandchildren. Sefer Bereishis ends with a description of the family relationship which existed between Yaakov and his children and grandchildren in order to portray what a family should look to create: a strong bond from one generation to the next.