The first time Rav Yaakov Yitzchok arrived in Rovna to see Rav Dov Ber, later known as the Mezritcher Maggid and successor of the Baal Shem Tov as the leader of the Chassidic movement, the Maggid was bed ridden with a life-threatening illness.
Rav Yaakov Yitzchok wasted no time and headed straight for the mikvah whereupon he immersed himself in the freezing cold waters as an act of self-sacrifice to add merit and heal the sick tzaddik.
The waters were so icy that he fainted. No sooner had he passed out when the Maggid, Rav Dov Ber opened his eyes. His fever broken, he called those gathered around his bedside and urged, “Quick! Rush to the mikvah and save a Jewish life! He certainly deserves it!” And so, the Chozeh saved the Maggid’s life. (Kisvei Rav Yoshe Shuv of Brisk 28)
