JAFFE, MORDECAI-GIMPEL (1820–1891), rabbi, member of the *Ḥibbat Zion movement. Born in Utyana, Kovno district, Jaffe studied at the Volozhin yeshivah and became well known for his religious scholarship and his Hebrew and general education, the latter acquired by his own efforts. When Moses *Montefiore visited Russia in 1846, Jaffe headed a delegation to present him with a memorandum on the economic situation of the Jews of Derechin, where Jaffe served as rabbi. In the memorandum he proposed that Montefiore try to influence the Russian government to agree to the following suggestions: allotting land to Jews for farming, permitting Jews to acquire land and to settle in towns outside the *Pale of Settlement, rescinding the expulsion order to Jews settled in villages among Christian peasants, restoring the right of Jews to settle their disputes in Jewish courts, etc.
In 1855, Jaffe was appointed rabbi in the small town of Ruzhany in the Grodno district, and he remained at his post there for over 30 years. He opposed any ideas of religious reform, such as those of Moses Leib *Lilienblum. Jaffe supported the activities of the Ḥevrat Yishuv Ereẓ Israel (Central Committee for Jewish Colonization in Palestine), founded by Ẓevi Hirsch *Kalischer, and established a society of this kind in his community. He also joined the Ḥibbat Zion movement upon its establishment. When Baron Edmond de *Rothschild, urged by Samuel *Mohilewer, agreed to found an agricultural settlement in Ereẓ Israel with farmers from Russia, Jaffe aided in the aliyah of Jewish farmers from a village near Ruzhany.
At the end of 1888, he went to Ereẓ Israel, and after a few months in Jerusalem settled in *Yehud, near Petaḥ Tikvah, where he headed a yeshivah with eight students. During the she mittah controvery (1889), Jaffe demanded strict compliance with the laws of the Torah. Of his numerous writings, only his comments to the Midrash on Psalms appeared in his lifetime (1865). After his death, his son published some of his works, including the book Zikhronot Mordekhai (1923), in which his letters, memoranda, precepts to his sons, and his will were incorporated.
B. Jaffe, Ha-Rav mi-Yehud (1957); A. Druyanow, Ketavim le-Toledot Ḥibbat-Ẓiyyon ve-Yishuv Ereẓ-Yisrael, 3 (1932), 888–92; Y.L. Maimon, Sarei ha-Me'ah, 5 (1961), 277–85; EẒD, 2 (1960), 522–38; I. Klausner, Be-Hitorer Am (1962), index; idem, Mi-Katoviẓ ad Basel, 2 (1965), index.