(d. 1729), Sabbatian preacher. Mordekhai of Eisenstadt was born in Alsace (according to sources in Prague) around 1650. He was a pupil of Natan of Gaza and Avraham Cardozo. In the 1670s, he came to Nikolsburg, the center of Sabbatianism in Moravia. Thereafter he led an itinerant life, traveling through Bohemia, Moravia, Hungary, Germany, and Poland. Between 1678 and 1680, he was active as one of the first Sabbatian propagandists in Poland–Lithania. During his wanderings, he acquired the nickname Mokhiaḥ (“Rebuker”) and became famous for his talents as a preacher and for his ascetic conduct.
After the death of Shabetai Tsevi in 1676, Mordekhai ben Ḥayim claimed that the messiah had only gone into occultation and would return in three years to complete the process of redemption. Mordekhai also taught about the necessity of Shabetai Tsevi’s conversion to Islam and mused that it needed to be supplemented by a conversion to Christianity—a doctrine later elaborated by Jakub Frank. Mordekhai also related a number of political prophecies, including one concerning the readmission of the Jews into Spain. Despite his radical theology, however, he emphasized the need to lead a strictly pious life.
In 1678, Mordekhai ben Ḥayim became associated with the circle of Italian Sabbatians led by Avraham Rovigo and Binyamin Kohen. He accepted Rovigo and Kohen’s brand of ascetic Sabbatianism, which deviated from halakhic practice only in abolishing the fast of the Ninth of Av. He achieved significant popularity in Italy, which attracted the attention of the Inquisition, and led to his leaving Italy around 1681. Thereafter, Mordekhai ben Ḥayim claimed that he himself was a messiah. He resumed his travels but did not acquire a large following.
Mordekhai ben Ḥayim died in Pressburg (Bratislava) in 1729. The inscription on his tombstone reads: “Here lies the Rebuker, our great Teacher and Rabbi Mordekhai son of Yesha‘yah Ashkenazi from the Land of Alsace.” His brother—who often traveled with him—was probably the famous rabbi Me’ir Eisenstadt; his son was the eminent Talmudist Yehudah Leib Mokhiaḥ.
Heinrich Graetz, History of the Jews, vol. 5 (1895; rpt., Philadelphia, 1941), pp. 208–209, 212; Oskar K. Rabinowicz, “Schabbatianer in Maehren im 17. und 18. Jahrhundert,” unpublished manuscript, Gershom Scholem Archives, no. 1599/143, Jewish National and University Library, Jerusalem.