As we learned on yesterday’s daf, if a non-Jew owned an animal, even if the firstborn was acquired by a Jewish person, it would not be subject to the laws of bekhor. On today’s daf we find a discussion about a situation where the Jew and the non-Jew were partners in the animal. Rabbi Yehuda rules that if a Jew and a non-Jew were partners in the firstborn, the Jew is obligated to pay half of the value of the firstborn to a kohen. The Sages disagree, arguing that such an animal is entirely free from the laws of the firstborn.
In the context of this discussion, the Gemara relates the following story:
There was a female convert whose gentile brothers gave her animals to fatten and would then divide the profits with her. She came before Rava to ascertain her obligation in the laws of the firstborn with regard to these animals. Rava said to her: “There is no authority that pays any attention to the ruling of Rabbi Yehuda who said: An animal owned in partnership with a gentile is subject to the law of the firstborn.”
Conversion to Judaism was a relatively infrequent occurrence in Babylonia, and it appears that the Persian government looked askance at people who were interested in converting. Nevertheless, during the reign of Shevor Malka -Shapur – which was during Rava’s time, we find a number of conversions that took place, most of which, like the story related in our Gemara, took place in the city of Meḥoza, Rava’s hometown. It is possible that this phenomenon is related to the close ties that existed between the king, Shevor Malka, and the Jewish community and its leaders in Babylonia.