Isaac ben Judah

{{Short description|12th-century rabbi}}

{{Distinguish|Isaac bar Judah|Isaac ben Judah HaLevi}}

{{Infobox Jewish leader

| honorific-prefix = Rabbi

| name = Isaac ben Judah

| native-name = {{Lang|he|יצחק בן יהודה}}

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| birth_place = Lorraine

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| father = Judah

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Isaac ben Judah of Mainz ({{Langx|he|יצחק בן יהודה}}) was a Talmudist of the eleventh century; teacher of Solomon ben Isaac (Rashi).{{Cite encyclopedia|encyclopedia=Encyclopaedia Judaica|title=ISAAC BEN JUDAH OF MAINZ|year=1971|publisher=Keter Publishing House|volume=9|location=Jerusalem|page=23}}{{cite book|author= Abraham Zacuto|author-link=Abraham Zacuto |script-chapter=he:מאמר חמישי דורות אחרונים|chapter-url=https://www.hebrewbooks.org/pdfpager.aspx?req=46738&st=&pgnum=219|script-title=he:יוחסין השלם |language=he|page=217| access-date=May 7, 2023}}{{cite book|author=Salomon Buber|author-link=Salomon Buber|script-chapter=he:ר' יצחק בר יהודה|chapter-url=https://hebrewbooks.org/pdfpager.aspx?req=8961&st=&pgnum=19|script-title=he:מבוא לספר האורה|language=he|page=15|access-date=May 7, 2023}}

He was a native of Lorraine ("Ha-Pardes," 35a), but settled early in life in Germany, where he studied under Eleazar ha-Gadol.

Isaac occupied successively the positions of head of the rabbinical schools of Mainz and Worms; it was in the latter place that he became the teacher of Rashi. Isaac was one of the greatest Talmudic authorities of his time, and his name is frequently mentioned in rabbinical literature. He was the author of commentaries on the Talmud, some of which are cited by Rashi (Ber. 39a,{{cite wikisource|title=רש"י על ברכות לט א |wslink=ברכות_לט_א#רש"י|wslanguage=he}} 57a; R. H. 28a{{cite wikisource|title=רש"י על ראש השנה כח א|wslink=ראש_השנה_כח_א#רש"י|wslanguage=he}}); and his responsa are scattered in the "Pardes ha-Gadol", the "Liḳḳuṭe Pardes", the {{Ill|Or Zarua (book)|lt="Or Zarua"|he|אור זרוע}}, the {{Ill|Shibbole ha-Leḳeṭ|lt="Shibbole ha-Leḳeṭ"|he|שיבולי הלקט}}, the "Mordekai", and the responsa of Meir of Rothenburg.

In a French Maḥzor manuscript quoted by Leopold Zunz ("Zur Geschichte und Literatur" p. 622), Isaac is mentioned as having been at one time head of the rabbinical school of Paris; this, however, is highly improbable.{{JewishEncyclopedia|inline=1|article=ISAAC BEN JUDAH|url=https://www.jewishencyclopedia.com/articles/8184-isaac-ben-judah|author=Solomon Schechter and Isaac Broydé}}
Jewish Encyclopedia bibliography:

• Weiss, Dor, iv. 319;
• Michael, Or ha-Ḥayyim, p. 502;
• Gross, Gallia Judaica, pp. [https://archive.org/details/galliajudaicadi00grosgoog/page/295/mode/1up 295], [https://archive.org/details/galliajudaicadi00grosgoog/page/507/mode/1up 507].