The Gemara asks: With regard to what principle do they disagree? The Gemara suggests that they disagree with regard to the issue of a more inclusive prohibition, and this dispute pertains to the status of a more inclusive prohibition specifically according to the opinion of Rabbi Yosei. Rabbi Ḥiyya holds that Rabbi Yosei is of the opinion that in the case of a more inclusive prohibition, one is liable on two counts. Bar Kappara holds that Rabbi Yosei is of the opinion that one is liable only on one count.

The Gemara asks: And what more inclusive prohibition is there here in these cases? Granted, in the case of a non-priest who served in the Temple on Shabbat, initially he was permitted to perform labor every day and was prohibited from engaging in the Temple service. When Shabbat came, since he is now prohibited from engaging in prohibited labor in all contexts due to Shabbat, he is also prohibited from engaging in labors related to the Temple service due to Shabbat. Indeed, the additional prohibition of Shabbat was added to the previously existing prohibition against performing service in the Temple. This is a more inclusive prohibition since it also includes prohibited labor outside of the Temple.

The same is true with regard to a blemished priest who served in the Temple while ritually impure: Initially, prior to his becoming ritually impure, he was allowed to eat from the consecrated animals but was prohibited from performing the Temple service, like all blemished priests. When he was rendered ritually impure, since he is now prohibited from eating of the consecrated items, he is also prohibited from performing the Temple service due to that same ritual impurity. There is, then, a more inclusive prohibition here. However, with regard to the case of a bird that was killed by pinching, you find that the prohibition against the eating of consecrated items by a non-priest and the prohibition against eating an unslaughtered animal carcass take effect simultaneously. You do not, however, find a more inclusive prohibition here as there was no original prohibition that took effect beforehand. Instead, this is a case of two prohibitions that take effect simultaneously.

Rather, the previous explanation is rejected and the Gemara suggests instead that they disagree with regard to an additional prohibition that takes effect simultaneously, and this dispute pertains to the status of these prohibitions specifically according to the opinion of Rabbi Yosei. Rabbi Ḥiyya holds that Rabbi Yosei is of the opinion that one is liable on two counts in cases of prohibitions that take effect simultaneously. And bar Kappara holds that Rabbi Yosei is of the opinion that one is liable only on a single count.

The Gemara challenges this explanation: But here, in the first two instances, what case of simultaneous prohibitions is there here? In the two previous cases the prohibitions took effect one after the other, and not simultaneously. The Gemara answers that these cases can also be interpreted as occurring simultaneously as follows: With regard to the non-priest who served on Shabbat, this would be in a case where a minor grew two pubic hairs, signaling adulthood on Shabbat. Before that point he was considered a minor and therefore not liable for his actions. Therefore, this is a case where the prohibition against serving as a non-priest and the prohibition against violating Shabbat took effect together.

With regard to the case of one who was blemished, this can be explained as well: This is referring to a case where a minor grew two pubic hairs and was immediately rendered ritually impure. This is a case where the prohibition with regard to a blemished priest and the prohibition with regard to ritual impurity took effect together. Alternatively, it could be a case where he cut off his finger with a ritually impure knife. Here, the cut and removal of his finger rendered him simultaneously blemished and ritually impure.

Following this clarification of the dispute, the matter is now considered from a different angle: Granted, according to the opinion of Rabbi Ḥiyya, the dispute between his version of Rabbi Yehuda HaNasi’s ruling and that of bar Kappara can be explained as follows: When Rabbi Yehuda HaNasi taught Rabbi Ḥiyya, he taught him according to the opinion of Rabbi Yosei, and Rabbi Yosei holds that there are cases where two prohibitions can both take effect. And when Rabbi Yehuda HaNasi taught bar Kappara, he did so according to the opinion of Rabbi Shimon who holds that a new prohibition can never take effect where another prohibition already exists. Therefore, Rabbi Ḥiyya could understand why bar Kappara insisted on his opinion. Rabbi Ḥiyya thought that bar Kappara was in fact relating an accurate statement of Rabbi Yehuda HaNasi, as Rabbi Yehuda HaNasi was relating to the opinion of Rabbi Shimon. Rabbi Ḥiyya assumed that bar Kappara did not understand that Rabbi Yehuda HaNasi’s statement was not in accordance with Rabbi Yosei’s opinion. According to bar Kappara, however, was Rabbi Ḥiyya then telling a falsehood? How would bar Kappara relate to Rabbi Ḥiyya’s oath? Did he think that Rabbi Ḥiyya would swear that he heard words from Rabbi Yehuda HaNasi that were never said?

Rather, this must be explained differently: Rabbi Ḥiyya and bar Kappara disagree with regard to cases where two prohibitions take effect simultaneously, and this dispute pertains to the status of these prohibition specifically according to the opinion of Rabbi Shimon. It could be suggested that when the two prohibitions take effect simultaneously, Rabbi Shimon would concede that they both take effect. However, this explanation raises a difficulty as well: Granted, according to Rabbi Ḥiyya it is clear why he was swearing. He did so in order to exclude the understanding of Rabbi Shimon’s opinion that was based on his presumed opinion. As it was known that Rabbi Shimon holds that a new prohibition cannot take effect where another prohibition exists; this is the default understanding of his opinion. Therefore, it was incumbent upon Rabbi Ḥiyya to take an oath in order to emphasize that despite Rabbi Shimon’s general opinion, in cases where the prohibitions take effect simultaneously, he would concede that both prohibitions can take effect. However, according to bar Kappara, why was it necessary to swear? It would have sufficed for him simply to make his statement, as it concurs with the default understanding of Rabbi Shimon’s opinion. The Gemara comments: Indeed, this is difficult.

One can raise a difficulty with this explanation from a different angle as well: Granted, according to bar Kappara, when Rabbi Yehuda HaNasi taught him, he taught him according to the opinion of Rabbi Shimon, who holds that two prohibitions cannot take effect even in cases when they occur simultaneously, and when he taught the ruling to Rabbi Ḥiyya it was according to the opinion of Rabbi Yosei. Accordingly, Rabbi Ḥiyya did in fact swear that he heard that one is liable only on one count, but he wrongly understood that this was Rabbi Shimon’s opinion. However, according to Rabbi Ḥiyya, who holds that Rabbi Shimon concedes that in cases where the prohibitions take effect simultaneously one is liable for both, was bar Kappara lying? His statement would accord neither with Rabbi Shimon nor with Rabbi Yosei.

The Gemara answers: Rabbi Ḥiyya could have said to you that this is what transpired: When Rabbi Yehuda HaNasi taught him, bar Kappara, he taught him two cases involving exemptions, i.e., the cases of a non-priest who served in the Temple on Shabbat and that of the blemished priest who served while ritually impure. Both of these are cases of more inclusive prohibitions, and he was informing bar Kappara that Rabbi Shimon holds them liable on only one count, because Rabbi Shimon holds that a prohibition takes effect where another prohibition already exists only if the prohibitions take effect simultaneously, but not in cases of more inclusive prohibitions.