Rav Yitzchok was the son of Rav Yosef Sprawiedliwy (Polish for ישר – Righteous or Just) and Yenta Di Nevia (the Prophetess).
His mother was a great Tzadekes; she would immerse herself several times a day and davened wearing a tallis. According to tradition, she would interrupt such mundane household activities as sweeping the house to answer Kodosh, Kodosh, Kodosh, to the heavenly hosts’ kedusha, which she could hear. She earned the moniker “Prophetess” after her husband complained of her behavior to the Ba’al Shem Tov, only to receive the response that she has open eyes and can see and hear things that others do not, and so she became known as Di Nevia. The Chassidim treated her like a Rebbe, asking for her berochos. In return, she asked for gifts of food, which she would distribute to the poor.
Rav Yitzchok was descended from Rav Yitzchok Chaijes, Av Bais Din of Prague, mechaber of Api Ravravi. When he lived in Ostrog, he was one of the ten Jews who studied in Rav Yuzpa’s Bais Medrash, among the greatest lamdonim in town. He was also the Maggid and mochiach in Brod in the Bais Medrash of Rav Yitzchok of Hamburg during his tenure as Rav of Brode. Although he knew of and approved of the Ba’al Shem Tov, according to some, he was a colleague rather than a talmid.
The Ba’al Shem testified before Rav Yitzchok’s son, Rav Michel of Zlotshuv, regarding his father, that Rav Yitzchok “was given such a lowly soul that almost none have ever been given one so low, yet he elevated it to the heights of the Tanna Rav Shimon Bar Yochai!” (Agra Depirka)
He passed away on 7 Nissan 5510/1750 (or 5504/1744). Some of his Divrei Torah appeared alongside those of his sons in Mayim Rabim. His son was the famed Rav Yechiel Michel of Zlotshuv. His sons-in-law were Rav Avner Kasvan and Rav Yochonon Litvak of Radvil.
