Parshas Vayigash tells us that Yaakov, before bringing his family to Egypt, “sent Yehudah ahead of him to prepare [l’horos] ahead of him in Goshen” (Bereishis 46:28).
“L’horos,” says the Midrash, is related to the word “Torah.” Yaakov’s purpose in sending Yehudah ahead of him was to establish a yeshiva in Egypt from which would issue hora’ah – Torah rulings. Whenever Jews come to a new place, their first concern should be to create an environment enabling them, particularly their youth, to study Torah.
But why did Yaakov send Yehudah? Surely his son Yosef, who was already in Egypt, could have more easily established this Torah academy. Yaakov had taught Yosef all the Torah he had learned from Shem and Eiver (Rashi, ibid. 37:3), and the wagons Yosef sent him 22 years later indicated that he still remembered everything despite his difficult years in Egypt (Rashi, ibid. 45:27). So why didn’t Yaakov ask Yosef to establish a yeshiva?
The answer lies in the difference between Yosef and his brothers: The latter lived like their ancestors Avraham, Yitzchak, and Yaakov. They were shepherds and thus able to avoid over-involvement in worldly affairs. They could spend much time serving G-d through prayer, meditation, and Torah study (see Yoma 28b). “Shepherds of sheep are your servants, both we and our ancestors,” the brothers told Pharaoh (ibid. 47:3).
Yosef, on the other hand, was involved in worldly affairs. He was on such a high spiritual level that this involvement didn’t disturb his service of G-d. Even in his youth, he stayed home while his brothers left to take care of the sheep (ibid. 37:12). Later, after being sold into slavery, Yosef administered his master’s household, which involved (as least partially – see Onkelos, ibid. 39:11) “checking the accounting books” – i.e., intellectual work.
He did similar work during his 12-year imprisonment (see Onkelos, ibid. 39:22), and of course after he became Pharaoh’s viceroy as he took care of affairs of the state. Yet, despite all this worldly involvement, he was able to retain his deep soul-attachment to G-d, constantly mentioning His name even to idol worshippers such as Potiphar and his wife, Pharaoh’s ministers, and eventually Pharaoh himself.
Although the three patriarchs and Yosef’s brothers were all attached to G-d continually, they were able to do so only by withdrawing from over-involvement in material affairs and living the pastoral lifestyle of shepherds. Yosef, however, was capable of being constantly aware of G-d’s presence even while being involved in worldly affairs.
Since Yosef possessed this ability, his soul was evidently on a far higher level than the souls of the brothers. But the level of his Torah study was not. In fact, because he was so involved in worldly affairs, he could reach the level of “his Torah study is his occupation,” which is the highest level of Torah study (a level that only the greatest of our Sages attained). Although his affairs were all in accordance with Torah and he remained a vehicle for G-d’s presence, he could not attain the ultimate level of unity with the Torah as someone who studies it constantly.
And that’s why Yaakov didn’t ask Yosef to establish the yeshiva and gave the task to Yehudah instead. Yehudah, like his other brothers, was removed from the world and therefore more deeply involved in Torah study. Only someone like him could establish a yeshiva with the true atmosphere of total immersion in Torah.
(Based on teachings of the Lubavitcher Rebbe)