The Bobover Rebbe told how once Rav Hillel was traveling by train, when he was seen by a Jew who had left the fold. Unfortunately, this Jew was known even to eat non-kosher food. When he alighted from the train and gazed upon the fine, spiritual features of the Tzaddik, he stood transfixed and was simply unable to take his eyes off Rav Hillel, who sat right near the door of the train. He stood in this manner transfixed for some time before he was able to move on.
When he came home, a curious change took place; his family remembered his eating habits to verge on the gluttonous, but now he had no appetite for anything at all and refused all meals! Finally, they were invited to a family affair where kosher food was served and he pounced upon the food with hunger! That was when the family realized what had happened; the vision of the saintly Tzaddik had so refined and purified the man, that he was simply unable from then on to eat non-kosher food! Such was the greatness of Rav Hillel of Kolomaya! (Bais Tzaddikim Ya’amod Bobov Vol. II page 77)
