Rabbah bar Naḥmani () (died c. 320) was a Jewish Talmudist known throughout the Talmud simply as Rabbah. He was a third-generation amora of the talmudic academies in Babylonia, which were in Asoristan, the Lower Mesopotamian part of the Sasanian Empire.

Biography Rabbah was a kohen descended from Eli the shofet.Rosh Hashana 18a He was a student of Rav Huna at Sura Academy and of Judah bar Ezekiel at Pumbedita Academy. Huna seldom decided a question of importance without consulting him.Compare Gittin 27a; Bava Metzia 18b; Bava Batra 172b; Yebamot 61b

His brethren in the Talmudic academies in Syria Palaestina wrote to Rabbah to move to Palestine, where he would find a teacher in Johanan bar Nappaha; it would be far better for him to have a guide than to rely on himself in his studies.Ketuvot 111a However, Rabbah never left Mesopotamia.All supposed evidence to the contrary was refuted by Bacher ("Ag. Bab. Amor," pp. 97 et seq.). In Shevuot 10b and Nedarim 57a, where Rabbah is asked by Rav Chisda, "Who will listen to you and your teacher R. Johanan?" the latter is only figuratively called Rabbah's teacher. (Jewish Encyclopedia)

Upon the death of Judah bar Ezekiel, Rabbah succeeded as resh mthivtā (; he held the post until his death 22 years later.Berachot 64a; Letter of Sherira Gaon, in Neubauer, "M. J. C." pp. 30-31 He is also said to have lived in poverty, but little else is known about his private life. Residents of the city of Pumbedita hated Rabbah for his criticism of their practice of fraud according to tractate Shabbat 153aRashi ad. loc. but loved by his students.

The academy achieved its height under his leadership, and he attracted many new students.Bava Metzia 86a He initiated the Kallah, biannual month-long study gatherings, leading to the students being absent at the time of tax collections. The Sasanian emperor sent bailiffs to seize him; he fled from city to city and finally into a marsh, where his body was found in a thicket.Babylonian Talmud (Bava Metzia 86a) During the Kallah months, he is said to have attracted as many as 12,000 students.Bava Metzia 86a

According to Sherira ben Hanina, he was denounced to the emperor for causing twelve thousand men to be idle during the months of Elul in summer ( qayṭā) and Adar in winter ( saṯwā). The Talmud records that after his death, he was eulogized for seven days.

Rabbah's nephew was the great scholar Abaye (280–340), an orphan who he raised. He was succeeded by his son, who was also named Rabbah. Both Rabbah and Abaye were destined to die in the prime of their lives as they were descendants of Eli the Shofet, who was cursed that his descendants would die young. However, because Rabbah studied the Torah, he deserved to live to 40, whereas Abaye, who studied the Torah and performed extra acts of kindness, lived to the age of 60.Abbaye - The Talmudic Age, chabad.org

Teaching He was a great scholar, renowned for his abilities to argue texts, resolve contradictions, and find applications, which gave him the nickname "uprooter of mountains" ( ʿoqer hārkm),Berachot 64a as his studies exhibit the power of one who picks up mountains and grinds them against each other.Sanhedrin 24a He was also an exceptional teacher. He used to start every lecture with a joke or funny anecdote to get his students in a good mood.Talmud, Shabbat 30b He would test the judgment of his audience, implying mistaken law and waiting for his students to find the mistake.

Only about ten of Rabbah's aggadic teachings are recorded.Sanhedrin 21b, 26b; Shabbat 64a; Pesachim 68b; Megillah 15b; Hagigah 5b; Arachin 8b; Eruvin 22a; Gittin 31b He concentrated his attention on halakha, which he endeavored to elucidate by interpreting Mishnaic decisions and baraitot and by determining the fundamental reasons for the various Torah and rabbinical laws and explaining the apparent contradictions contained in them. He often asks: "Why did the Torah command this?" "Why did the sages forbid this?" He did not confine his interest to the practical laws of the Mishnah, however, like his teacher Judah bar Ezekiel. He studied all six orders of the Mishna according to tractate Ta'anit 24a,b and was the leading authority in the obscure subjects of nega'im and tumah and taharah.

He was not the author of Genesis Rabbah or the other midrashic works whose names end in "Rabbah."Abraham ibn Daud, "Sefer ha-Ḳabbalah," in Neubauer, "M. J. C." p. 58 Genesis Rabbah is named after Hoshaiah Rabbah, and the others are named after Genesis Rabbah.

References

Sources Encyclopaedia Judaica, 1972, Keter Publishing House, Jerusalem, Israel. Sefer Ha-Aggadah (Book of Legends), 1992, Schocken, New York.