Pirkoi ben Baboi פירקוי בן באבוי

The epistle was written about 4560 (800) and addressed to the communities of Kairouan and further west. He calls himself a student of Rava, the student of Rav Yehudai Gaon—that is, he speaks with the voice of the school of Sura at one remove. His argument is simple and hard: in the Land of Israel persecution tore the transmission, in Babylonia it was never broken—therefore trust the Babylonian.

That argument won: the world learns the Babylonian Talmud. But the worth of a source is set also by what it fights: from his own epistle we know how the Land of Israel lived and prayed—testimony taken down by an adversary. The text came to light among the Genizah fragments and has been printed since the start of the twentieth century.