ריטב"א

Rabbeinu Yom Tov ben Avraham Asevilli (c. 5010/1250–c. 5090/1330), the Ritva, was among the greatest of the rishonim of Spain, and his chiddushim on the Talmud are learned in every yeshiva in the world — famed for joining depth of analysis to a clarity of language that opens the sugya to every learner. Born in Seville, he learned in Barcelona under his rebbe muvhak the Ra’ah, Rav Aharon HaLevi, whom he cites with reverence, and under the Rashba; from 5040/1280 he sat as dayan in Zaragoza, where his beit din was called by his generation “the great and beautiful beit din,” and the she’eilot of communities and batei din streamed to him even in his teachers’ lifetimes.

His Chiddushei HaRitva, written in a longer and then a concise recension, weave together the derech of the Ramban‘s school — the Rashba, the Ra’ah — with the Tosafot of France, sifting and deciding between them; the Beit Yosef treats him as a halachic authority, and his volumes stand on the shelf of every lomdan beside those of his teachers. He honored both the Rambam and the Ramban — learning the Moreh Nevuchim and writing the Sefer HaZikaron in its defense — while holding fast to the derech of his own teachers, whom he calls “rabbeinu hagadol.”

His deepest teaching concerns machloket itself: when Moshe ascended to receive the Torah, he was shown for every matter forty-nine faces to forbid and forty-nine to permit — and Hashem said: this is given over to the chachamim of Yisrael in every generation, and the decision shall be as they decide. The disputes of the Talmud are not a flaw in the mesorah but its fullness. He left as well responsa, a peirush on the Haggadah of Pesach, and commentaries on the halachot of the Rif.