RabbiNissim Ben Jacob (Rav Nissim Gaon, 990-1062) is best known today for his Talmudic commentary HaMafteach.
Biography
Rav Nissim studied at the KairouanYeshiva, initally under his father, Jacob ben Nissim, and then under Chushiel, who succeeeded Jacob as head of the Yeshiva. Nissim himself later became head of the Yeshiva; in this capacity he is closely associated with Chananel son of Chushiel. His most famous student is probably Isaac Alfasi. Rav Nissim maintained an active correspondence with Hai Gaon and with Shmuel Hanaggid. Some consider Nissim and Chananel to constitute the first generation of Rishonim.
Works
The commentary Sefer Mafteach Manulei Hatalmud (The book of the Key to the Talmud - HaMafteach) on some of the tractates is included on the main pages of many editions. The work is essentially a Talmudic cross-reference. In it Rav Nissim brings down sources for Mishnaic quotes, identifying obscure allusions to other places in Talmudic literature.
Hananeel's contemporary NissimbenJacob, of Kairawan, who corresponded with Hai Gaon of Pumbeditha as well as with Samuel the Nagid in Spain, likewise wrote on the Talmud, and is probably the author of a collection of Ma`asiyyoth or edifying stories, besides works now lost.
Rashi was a pupil of Jacobben Yaqar, and studied at Worms and Mainz.
Of the same school were Menahem ben Simeon of Posquieres, a commentator, who died about the end of the 12th century, and Moses benJacob of Coucy (13th century), author of the Semag (book of precepts, positive and negative) a very popular and valuable halakhic work.
In this work Nissim aimed to meet the difficulties in the study of the Talmud, which for his contemporaries consisted chiefly in the fact that they were not so well versed therein as the ancient teachers.
Nissim did not confine himself to quoting references, but expounds them in their connection with the text; thus his work is at the same time a Talmudical commentary.
Nissim had a method of his own for the study of the Talmud, using very largely the Palestinian Talmud, which hitherto had been generally neglected.