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Yitsḥak ben Ya‘akov ha-Lavan of Prague

(fl. 12th century), Talmudic scholar. Also known as Yitsḥak of Bohemia and Yitsḥak of Regensburg, Yitsḥak ben Ya‘akov reputedly acquired the nickname ha-Lavan (White) because of the color of his hair, but according to other sources the name was connected to that of the river Labe (Elbe). Yitsḥak ha-Lavan lived and worked in Prague, although it is not certain that he actually came from Bohemia. He studied in Germany and France and was a student of Yitsḥak ben Asher ha-Levi and Ya‘akov ben Me’ir Tam (Rabenu Tam). Throughout his life he associated with members of the Prague school of Tosafists (including Yitsḥak ben Mordekhai and Eli‘ezer ben Yitsḥak), who maintained ties to the centers of Jewish culture in northern France and Germany.

Yitsḥak ben Ya‘akov was regarded as a legal authority across Central Europe, including—among other places—Worms and Cologne, where he was called upon to give opinions on ritual questions. Among those who respected him were Yo’el ben Yitsḥak ha-Levi and his son Eli‘ezer ben Yo’el ha-Levi, Yehudah ben Kalonymos ben Mosheh, and Yonatan ben Yitsḥak. Yitsḥak ben Ya‘akov is also frequently cited by Yitsḥak ben Mosheh of Vienna in the work Or zaru‘a. Toward the end of his life, Yitsḥak ha-Lavan was active on the rabbinic court of Regensburg. It is also thought that he was in contact with followers of medieval German pietism (Ḥaside Ashkenaz).

Among Yitsḥak’s preserved works are Tosafot on the Talmudic tractates Yoma and Ketubot, which remained in manuscript until the mid-twentieth century and were finally published as Tosafot R. Yitsḥak ha-Lavan ‘al masekhet ketubot (1954) and Tosafot yoma (1956). References to Yitsḥak ha-Lavan appear in editions of Tosafot on tractates Yevamot, Ketubot, and Zevaḥim, and his influence is also evident in certain passages of Rabenu Tam’s Sefer ha-yashar. A piyut (liturgical poem), “Emunat melakhim natata” (1193), is also ascribed to him.

Yitsḥak ha-Lavan’s two brothers lived in Regensburg: Menaḥem (or Naḥman), a “learned rabbi”; and Petaḥyah, the famed traveler whose travel accounts were for centuries among the most popular educational books in the Jewish communities of the Diaspora. Yitsḥak ha-Lavan’s son, Ya‘akov ben Yitsḥak, is cited by Yitsḥak ben Mosheh of Vienna as his teacher.

Suggested Reading

Chaim Tykocinski, “Prag,” in Germania judaica, ed. Ismar Elbogen, Aron Freimann, and Chaim Tykocinski, vol. 1 (Breslau, 1934); Efraim Elimelech Urbach, Ba‘ale ha-tosafot (Jerusalem, 1986); Leopold Zunz, Literaturgeschichte der synagogalen Poesie (1865; rpt., Hildesheim, Ger., 1966).



Translated from Czech by Stephen Hattersley