Pesachim 28 - Shabbat December 19, 4 Tevet

Rabbi Yehuda finishes his arguments regarding why chametz should be burned before Pesach but the rabbis in the end win the debate and contradict Rabbi Yehuda from within his own opinion. The rabbis hold that one breaks it into pieces or throws the chametz into the river before throwing into the river, does one also need to break it up into pieces. The same question is asked on a mishna from Avoda Zara 43. Raba and Rav Yosef each distinguish between the two cases but each one in an opposite manner. Chametz that a gentile owned over Pesach is permitted to a Jew after Pesach but if owned by a Jew on Pesach, it is forbidden to benefit from after Pesach. The gemara questions - according to who is this mishna? It doesn't seem to match either of three opinions brought in a braitia regarding from when and until when is chametz forbidden by a negative transgression by Torah law and is it forbidden to benefit from. First the gemara brings sources for the different opinions and then explains why it seems the mishna doesn't correspond to any of these opinions.