Rabbi Isaac ben Jacob or Yitzhak ben Yaakov,

nickname A nickname is a substitute for the proper name of a familiar person, place or thing. Commonly used to express affection, a form of endearment, and sometimes amusement, it can also be used to express defamation of character. As a concept, it is ...

d ''"ha-Lavan"'' or "the white" was a 12th-century

rabbi A rabbi () is a spiritual leader or religious teacher in Judaism. One becomes a rabbi by being ordained by another rabbi – known as ''semikha'' – following a course of study of Jewish history and texts such as the Talmud. The basic form of ...

of Bohemia. He was a

Tosafist The Tosafot, Tosafos or Tosfot ( he, תוספות) are medieval commentaries on the Talmud. They take the form of critical and explanatory glosses, printed, in almost all Talmud editions, on the outer margin and opposite Rashi's notes. The auth ...

and liturgical poet who flourished at Prague in the late 12th century. He was the brother of the renowned traveler Petachiah of Regensburg. He was among the earliest of the

tosafists Tosafists were rabbis of France and Germany, who lived from the 12th to the mid-15th centuries, in the period of Rishonim. The Tosafists composed critical and explanatory glosses (questions, notes, interpretations, rulings and sources) on the Ta ...

("ba'ale tosafot yeshanim"), a contemporary of Rabbi Eleazar of Metz, and a pupil of

Rabbenu Tam Jacob ben Meir (1100 – 9 June 1171 (4 Tammuz)), best known as Rabbeinu Tam ( he, רבינו תם), was one of the most renowned Ashkenazi Jewish rabbis and leading French Tosafists, a leading ''halakhic'' authority in his generation, and a gra ...

. According to Recanati, Isaac directed the yeshivah of Ratisbon. He also lived at

Worms Worms may refer to: *Worm, an invertebrate animal with a tube-like body and no limbs Places *Worms, Germany, a city ** Worms (electoral district) * Worms, Nebraska, U.S. *Worms im Veltlintal, the German name for Bormio, Italy Arts and entertai ...

for a time. Isaac is mentioned frequently in the

Tosafot The Tosafot, Tosafos or Tosfot ( he, תוספות) are medieval commentaries on the Talmud. They take the form of critical and explanatory glosses, printed, in almost all Talmud editions, on the outer margin and opposite Rashi's notes. The auth ...

, and Isaac ben Moses, in his ''Or Zarua'', No. 739, quotes Isaac ben Jacob's commentary on

Ketubot A ketubah (; he, כְּתוּבָּה) is a Jewish marriage contract. It is considered an integral part of a traditional Jewish marriage, and outlines the rights and responsibilities of the groom, in relation to the bride. In modern practice, ...

, a manuscript of which exists in the Munich Library (No. 317). He is also mentioned in a commentary to the

Pentateuch The Torah (; hbo, ''Tōrā'', "Instruction", "Teaching" or "Law") is the compilation of the first five books of the Hebrew Bible, namely the books of Genesis, Exodus, Leviticus, Numbers and Deuteronomy. In that sense, Torah means the ...

written in the first half of the 13th century. There is a piyyuṭ signed "Isaac b. Jacob," whom Zunz"Litcraturgesch." p. 313 supposes to be Isaac ben Jacob ha-Lavan.

References

* Its bibliography: *Azulai, Shem ha-Gedolim, i.; *

Michael Michael may refer to: People * Michael (given name), a given name * Michael (surname), including a list of people with the surname Michael Given name "Michael" * Michael (archangel), ''first'' of God's archangels in the Jewish, Christian and ...

, Or ha- Ḥayyim, p. 507; *Zunz, Z. G. pp. 33, 42, 45, 80; *Grätz, Gesch. 3d ed., vi. 236; * Fuenn, Keneset Yisrael, p. 627. {{DEFAULTSORT:Isaac Ben Jacob Ha-Lavan Rabbis from Prague Tosafists 12th-century Bohemian rabbis