Yahrtzeit of Rabbi Menachem Mendel of Kotzk, Poland (1787-1859), the great chassidic leader known as the Kotzker Rebbe. He was said to be completely uncompromising in the quest for faith, honesty and truth. He abhorred rote piety, and taught his followers that they must renew their quest for self-knowledge and truth on a daily basis. He is known for his sharp wit and catchy phrases, for example: "Where is God? Wherever you let Him in."