Of Yosef’s two sons, Menashe was the eldest and Ephraim the youngest. Yet when Yaakov blessed them he gave the blessing of the Bechor to Ephraim and not to Menashe. Re’uven was Yaakov’s Bechor and when Yaakov blessed his own children he should have given the priesthood and kingship of the Jewish people to him. Yet he does not. He gave it to Levi and Yehudah instead.
Yaakov, who was the youngest son of Yitzchak, took the blessings of the Bechor from his father instead of Esav who was the real Bechor. At a much later date we find Hashem gives the leadership of the Jewish people to Moshe and not to the Bechor Aharon. Centuries later, David is proclaimed king of Israel and he was the youngest of Yishai’s children.
We see this pattern throughout the Tanach. The Bechor plays an important role in Judaism. When children inherit their father, the Torah prescribes that the Bechor gets a double portion. The Bechor is also given preference over his brothers in Jewish law when it comes to inherit the position of the role his father held in the community.
Yet we see from Yaakov’s actions, and from the other examples mentioned above, that this privilege is not automatic. It must be earned and the Bechor must be capable of properly fulfilling the functions this position requires. Not every Bechor is worthy of this privilege. Not every Bechor has the talent and the capacity to fulfill the responsibilities and obligations of this position.