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Isaac ben Abraham


ISAAC BEN ABRAHAM (Riẓba ; 12th century), French tosafist. Isaac is variously referred to as Riẓba, Riba, and Isaac ha-Baḥur of Dampierre. He was the pupil of Isaac b. Samuel ha-Zaken and also studied for a time under Jacob *Tam. He was not a pupil of *Judah b. Isaac-Judah, Sir Leon, as a number of scholars have thought (see Urbach, Tosafot, 269 n. 29). His brother was *Samson of Sens and his maternal grandfather, *Samson of Falaise. He succeeded his teacher as head of the yeshivah of Dampierre.

No complete work by him has survived, but his statements are cited in the tosafot to various tractates, chiefly Eruvin, Yoma, Mo'ed Katan, Yevamot, Ketubbot, Kiddushin, Nedarim, Bava Kamma, and Zevaḥim. He wrote numerous responsa, some of which are quoted in the Haggahot Maimuniyyot, the Or Zaru'a and in other works. During the Maimonidean controversy, Meir b. Todros Abulafia, an opponent of the books of Maimonides, approached him in 1202 to express his opinion. Among those who addressed problems to him was Jonathan b. David, the leading scholar of Lunel. There is mention of a work by him on the Passover seder, entitled Yesod Rabbenu Yiẓḥak b. Avraham be-Leilei Pesaḥ. His pupils included Nathan b. Meir and *Judah b. Yakar, the teachers of Naḥmanides, and Samuel b. Elhanan.


Gross, Gal Jud, 495; Michael, Or, no. 1073; Urbach, Tosafot, 219–26, 269 n. 29, 287 n. 14, 484 n. 106.

[Shlomoh Zalman Havlin]

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