According to the Mishna on yesterday’s daf when Yom Kippur fell out on a Friday – something that cannot happen today, with the establishment of a set calendar – there was a difficult situation regarding the sin offering that was ordinarily eaten by the kohanim immediately after Yom Kippur ended. Since a sin offering can be eaten only on the day that it was brought and the evening that follows, it had to be eaten on Friday night. Since it was Shabbat, however, and the Yom Kippur sin offering was not a Shabbat sacrifice, the meat could not be cooked. This problem was solved thanks to the Babylonian priests who were not so particular about their food, and were willing to eat the meat of the sacrifice when it was still raw.
On today’s daf, Rabba bar Bar Ḥana quotes Rabbi Yoḥanan as teaching that the people who were willing to eat raw meat in the Temple were not, in fact, Babylonians, rather they were from Alexandria in Egypt. The Mishna refers to people who were lacking in basic niceties of behavior “Babylonians,” since the Babylonians were hated by the Sages of the Mishna. Upon hearing this explanation – as well as a baraita that supported this clarification – Rabbi Yehuda, whose family roots were in Bavel commented that he was comforted by hearing this approach.
Several explanations are offered to explain why the Babylonians were hated by the Sages of the Mishna. Rashi suggests that the Babylonians were viewed as voracious eaters, who the Sages looked down on. When describing the behavior of ravenous people who were willing to eat raw meat, they therefore referred to them as Babylonians. Tosafot argue that the Sages of the Mishna who lived in Israel were angry that the Babylonian Jewish community had not moved to Israel en masse during the time of Ezra, which led to animosity towards them.
In his Yosef Da’at, Rabbi Yosef ben Arza points out that the Sages of the Mishna did not truly hate the Babylonians, for hatred is forbidden by the Torah both as a negative commandment (see Vayikra 19:17) and as a positive one (see the following passage 19:18). Rather, in this context, it simply means that they avoided interaction with the Babylonians, similar to the definition of someone who “hates” his fellow who is not allowed to testify about him in court, that is, someone who did not speak to his friend for three days out of anger (see Sanhedrin daf 27b).