Rashi cites the Midrash which interprets the word “l’horos” to mean “to teach.” This implies that Yehudah, the leader of the brothers, was sent ahead to establish a makom Torah, a House of Torah study, a yeshivah to prepare for the spiritual development of those coming to Egypt. What about Yosef, who was a tzaddik, who had maintained his spiritual level throughout his ordeal in exile, who certainly knew the country? Why was he not charged with founding the yeshivah?
The various commentators rationalize Yaakov’s decision. Horav Dov Eliezerov, zl, offers a practical solution to the problem. He relates that once in Brisk, on Yom Kippur night, Horav Chaim Soloveitchik, zl, went over to a wealthy Jew who had stayed up all night reciting Tehillim. He said to the man, “You know that in the Czar’s army every soldier has his specific position and post. If he is caught changing positions, he can be court-martialed or, even worse, shot. Everyone must serve in his designated position. You also have a position – due to being blessed with financial means. It would serve the community more if you had stayed in your position and inquired throughout the community as to who needs heat for the upcoming winter months. For you to recite Tehillim at this time is tantamount to leaving your post!”
Yosef was similarly charged by Heaven to oversee the sustenance of a world. This is the duty of a tzaddik, who, through his merit, the world is sustained. It is not his function to establish a yeshivah. That was to be left to Yehudah, the Rosh Yeshivah.
