(1868–1942), rabbi and Zionist leader. Born in Bobruisk, Belorussia, Yitsḥak Nissenbaum studied at various yeshivas, including in Volozhin and Vilna. In 1889, he settled in Minsk and was among the founders of the Safah Berurah association for the dissemination of the Hebrew language. When the Volozhin yeshiva closed in 1892, the clandestine national religious association Netsaḥ Yisra’el moved to Minsk, and Nissenbaum was appointed as one of its directors. In 1894, he moved to Białystok, where he served as the secretary of Ha-Merkaz ha-Ruḥani (an Orthodox organization that disseminated the ideas of Ḥibat Tsiyon [Love of Zion]) and as assistant to Rabbi Shemu’el Mohilewer. After Mohilewer’s death in 1898, Nissenbaum began to act as an itinerant preacher for Ḥoveve Tsiyon (Lovers of Zion, as the followers of Ḥibat Tsiyon were known), a position he filled for 11 years. In 1900, he moved to Warsaw and preached regularly in synagogues there.
Nissenbaum participated in the first conference of Mizraḥi in 1902 but did not join the movement, and his relations with it deteriorated two years later because of its support of the Uganda Proposal. In 1905, Nissenbaum visited Palestine; upon his return to Warsaw he participated in the founding and administration of the Ḥoveve Sefat ‘Ever association. In 1910, he joined the editorial board of its journal, Ha-Tsefirah.
Nissenbaum took part in the first convention of the Zionist Federation in Poland in 1916 and was a member of its central committee. He encouraged the immigration of ḥalutsim (pioneers), and founded an organization that offered them financial aid. In 1919, he finally joined Mizraḥi, and began to edit its weekly publication, Ha-Mizraḥi, after leaving his work with Ha-Tsefirah.
After an extended illness, which lasted from 1923 to 1931, Nissenbaum rejoined the leadership of Mizraḥi in Poland. He advocated observance of the laws governing the Sabbath and kosher food in Zionist institutions and in Zionist settlement activity, and called for social justice without class struggle. In 1937, he became president of Mizraḥi in Poland in place of Shemu’el Brodt. Nissenbaum was murdered during World War II, in the Warsaw ghetto.
Nissenbaum published many works on contemporary issues, Zionist policy, and religious matters. In addition to his newspaper articles, he published homiletic books in a nationalist spirit, among them Derushim ve-ḥomer li-derush (Sermons and Sermonic Material; 1903); Hagut lev (Thoughts of the Heart; 1911); Ha-Yahadut ha-le’umit (National Judaism; 1920); and Kinyane kedem (Ancient Possessions; 1931). Among his books on the history of the national movement are Ha-Dat veha-teḥiyah ha-le’umit (Religion and National Revival; 1920) and Masoret ve-ḥerut (Tradition and Freedom; 1939). Nissenbaum also wrote an autobiography, ‘Ale ḥeldi (Pages of My World; 1929), and edited basic books on Jewish studies in Hebrew.
Getzel Kressel, Leksikon ha-sifrut ha-‘ivrit, vol. 2, cols. 457–458 (Tel Aviv, 1967); Isaac Nissenbaum, Igrot ha-Rav Nisenboim, ed. Israel Shapiro (Jerusalem, 1956); Israel Shapiro, Ha-Rav Yitsḥak Nisenboim (Jerusalem, 1951).
Translated from Hebrew by Carrie Friedman-Cohen