Thought on Parshas Vayegash: “And Yakov sent Yehuda before him to Goshen, Lehoros”. Rashi explains that means to establish a yeshiva. The question is why Yehuda and not Levi, who represents the bearers of Torah, Yoru Mishpatecha L’Yakov?
Answer: There ae two types of talmidei chachomim. One is someone who stands above the yetzer hora (i.e. his yetzer is of limited strength), immersed in learning to the extent that there is little for the yetzer to do. The other is one who needs to vanquish his powerful yetzer, and does so successfuly. Levi represents the former, Yehuda the latter (see dvar torah about parshas Toldos).
One who has experienced, and overcome, the enticements of the yetzer can much more easily relate to the next generation, and help them overcome their difficulties. It is he who should become the next generations Rosh Yeshiva, helping others to accomplish what he has accomplished himself.