Today is the Yahrtzeit of Reb Tzadok HaKohain

Reb Tzadok HaKohain of Lublin, author of Pri Tzadik, Resisei Layla, and other works (1823-1900). The son of Reb Yaakov HaKohen, Rov of Kreisberg, Reb Tzadok studied only the revelead aspects of Torah (halacha and Talmud) until he was 24. Beginning in 1847, he learned only kabbalistic teachings. Rabbi Tzadok became a chasid of the Izbitcher Rebbe and a close friend of Reb Yehudah Leib Eiger. Upon the death of Rebbe Eiger in 1888, he agreed to take over the leadership of the chasidim. Rabbi Tzadok was a prolific writer whose works made an enormous impact with their profound thoughts. Besides writing numerous chidushim, he also wrote scholarly essays on astronomy, geometry, and algebra.