The Chida writes: I heard from Rav Hirsch of Balchov that when the Rebbe Reb Heschel of Cracow traveled to Vilna, fleeing the Cossacks and Chmielniczki during the riots of Tach and Tat, and he arrived before the Av Bais Din, Rav Sheptil Horowitz, mechaber of Vovei HoAmudim and son of the Shela HaKodosh, he did not recognize the Rebbe Reb Heschel or respect his greatness.
The Rebbe Reb Heschel then asked the son of the Shela to explain a Tosafos and he said he would study it but could not understand the Tosafos at all. He fasted and cried and then his own father, the mechaber of the Shela HaKodosh himself, appeared to him in a dream. His father explained to him the meaning and explanation of the Tosafos. He also admonished and warned him to honor the great Rebbe Reb Heschel for he had the soul of Rabbeinu Tam. Reb Sheptil awoke and immediately sent for the Rebbe Reb Heschel and honored him, explaining the Tosafos to him. The Rebbe Reb Heschel exclaimed and remarked in public, “The only way you got this explanation was a revelation from Heaven!” (Maagal Tov)
