In a recent book, Migrating Tales: the Talmud’s Narratives and Their Historical Context, Richard Kalmin seeks out the origins of numerous tales told in the Babylonian Talmud, which was compiled in the Persian empire around the year 500 CE. Kalmin argues that most are traceable not to Babylonian sources but to Jewish and non-Jewish sources in the eastern Mediterranean, then under the influence of Rome. In his review, Amit Gvaryahu discusses some implications that Kalmin may have overlooked:
Kalmin expertly uses the examples in his book to claim that the borders of empires [during this time period] were porous, and that ideas and traditions moved freely between them. This is undoubtedly correct and an important corrective to the inward gaze of rabbis . . . celebrated in scholarship in recent decades. But more than the borders of empire were porous, the Jews were tight-knit within themselves [even across political boundaries]. Any evaluation of the migration of traditions from the Roman East to Babylonia on biblical and Jewish themes must consider the possibility that these ideas were born and transmitted within the confines of the Jewish community, even though they may also be found in works associated with other groups, most notably Christians (to whom Kalmin points often in the book). . . .
In other words, even if many of these legends were likely influenced by Greek, Roman, or even early Christian sources, most originated among rabbis living in the land of Israel.