RAV KOOK ON VaYishlach Part 1: Reliance on Miracles

Miracles were no novelty for Rabbi Zeira. The Talmud in Baba Metzia 85a relates that the third-century scholar fasted for a hundred days in order to protect himself from the fires of hell. But Rabbi Zeira was not content with theoretical preparations. Once a month he would test himself by sitting down in a burning furnace, to see if he would feel the heat. He didn’t. (Once his clothes were singed, but that story is for another time.)