In Shab 116a the Gemara reports that various Amoraim disagreed as to whether they should attend an interdenominational discussion in a Bei Abidan. While Rashi (as quoted by Tosafot in A.Z. 17a, see below) understands this phrase as referring to an idolatrous temple, Tosafot suggest that it was merely a neutral place where discussions were held on various matters (see Tosafot A.Z. 17a, s.v. harheq mealeha), and presumably not a place for religious discussions—even though it is clear from the Gemara that there were kisvei qodesh kept there. Tosafot conclude that the Bei Abidan was not a place of minut (meqom minut mammash) but rather a place where gentile scholars would gather to debate their laws (nose’im ve-notenim be dinim). Indeed, Rav would not go, Shmuel would, and a certain Mar b. Yosef went enthusiastically, while Rava excused himself because of the difficulty of reaching that particular Bei Abidan. It is noteworthy that Tosafot seem to have had a different girsa in Shabbat, since they note that R. Nahman went and endangered himself. If this girsa is correct, it may have been the experience of his own rebbe that convinced Rava not to go to these debates, simply because of the dangers to which such attendance could lead. Despite all of this, however, it is noteworthy that kitvei ha-qodesh were kept there, indicating that there was some religious dimension to the discussions, and the fact that Rav could refuse to attend indicates that these were not medieval style “forced debates.”
Nevertheless, Rava was careful to maintain good relations with the non-Jewish communities around him, and thus did not refuse outright, but pointed to a large palm tree in the way, which, even if uprooted as the government offered to do, would leave a large hole in the road leading up to the Bei Abidan. Indeed, his excuse is plausible, since we know that his rebbe, R. Nahman, travelled in a palanquin (presumably carried by four men) (Git 31b), and Rava himself (when he became a dayyan of the Resh Galuta?) would do so as well (B.M. 73b); as convenient as a palanquin was for the passenger, a large hole in the ground would have made passage difficult and dangerous. He would send Bar Sheshakh, apparently a pagan Babylonian, gifts even on idolatrous festivals, since he was certain that Bar Sheshakh was not himself an idolater (AZ 65a). He also maintained friendly relations with Issur the Ger, and even once based a pesak on information he had gotten from him (AZ 70a). In this connection it should be noted that Mahoza, Rava’s town, was a suburb of the Persian winter capital of Ctesiphon—it was right across the river, and as a consequence, many non-Jews lived there. Both the Jewish Resh Galuta and the Christian bishop of Ctesiphon resided in Mahoza (called Kokhe by the Christians). We can understand then why there were many gerim in Mahoza (Qid 73a), as opposed to Pumbedita and Mata Mahasia, where R. Yehudah and R. Ashi observed that there were none (Ber 17b). The Mahozan Jewish community was, for better or worse, much more open to outsiders than Pumbedita’.
Yaakov Elman, “Rava as Mara de-Atra in Mahoza”, Hakirah 11 (Spring 2011), 66-68.