Achai Gaon

Achai Gaon (also known as Ahai of Shabḥa or Aha of Shabḥa, Hebrew: רב אחא [אחאי] משַׁבָּחָא) was a leading scholar during the period of the Geonim, an 8th-century Talmudist of high renown. He enjoys the distinction of being the first rabbinical author known to history after the completion of the Talmud. As he never actually became the Gaon of either of the two academies, the description "Gaon" attached to his name is a misnomer.

The gaon of Pumbedita having died, Aḥa was universally acknowledged to be the fittest man to succeed him. But a personal grudge entertained by the exilarch Solomon bar Ḥasdai induced the latter to pass over Aḥa, and to appoint Natronai ben Nehemiah, Aḥa's secretary, a man considerably his inferior in learning and general acquirements. Highly incensed at this slight, the eminent scholar left Babylonia and settled in Israel, about 752-753, where he remained until his death. Notwithstanding Steinschneider (Cat. Bodl. s.v.), who erroneously assigns 761 as the year, the exact date of his demise is unknown.

It must have been in Israel that Aḥa wrote his book entitled שאלתות ("Quæstiones" in the sense of disquisitions), as the title evinces; for this Aramaic word is employed in the sense of quæstio (the scientific investigation of a matter) by the Jews of Israel only (Shab. 30a). "Sheilta" is of Palestinian origin, as is shown by the words buẓina and bisha, which accompany it. S. Mendelsohn is quite correct in his explanation of the term (Rev. Ét. Juives, xxxii. 56). If, therefore, Simeon Kayyara made use of the "Sheiltot" in his Halakhot Gedolot, as is now certain, the statement of Abraham ibn Daud (according to whom Simeon's work was completed in 750) must be erroneous, since Aḥa did not leave Palestine before 752; and we know that Samuel Gaon, whose successor he was to have become, did not die before 751-752. There are also other evidences of Palestinian influence in Aḥa's work. For example, his treatise indicates that besides the Babylonian Talmud (which, in the nature of things, was his chief authority) he made frequent use of the Yerushalmi, and of Palestinian Midrashim, Leviticus Rabbah, Ecclesiastes Rabbah, and Tanḥuma, all of which at this time were quite unknown in Babylonia (indeed, even Saadia Gaon, almost two hundred years later, knew comparatively little of them).

...
Wikipedia