The Mishnah had taught: A person who the Chachamim released from excommunication [may take a haircut during Chol Hamoed].

What is the case? If they released him before the festival, let him take a haircut then! If they did not release him before the festival, he cannot take a haircut!

Rather, the case is when they released him before the festival and his 30th day will occur on the festival, as excommunication is not made for less than 30 days and "rebuke" is not made for less than 7 days.

Excommunication is not made for less than 30 days, as the Pasuk states (Bamidbar 11, 20), "until a month of days, until it comes out of your nose". "Rebuke" is not less than 7 days, as the Pasuk states (Bamidbar 12, 14), "Would she not be humiliated for 7 days?"

Rebbi would honor (his rich ignorant son-in-law called) Bar Elasa.

Bar Kafra to Bar Elasa: Everyone asks Rebbi (questions in Jewish law) and you do not!

Bar Elasa to Bar Kafra: What should I ask him?

Bar Kafra to Bar Elasa: Ask Rebbi the following riddle - It looks down from the heavens, there is panic inside its house, every winged creature is afraid. (Iyov 29,8), "Youths would see me and hide themselves, elders would arise and stand." One who flees from sin will speak with joy; one who is trapped, is trapped in his sin. (Bar Kafra wanted to allude to Rebbi that it was not correct for Rebbi to honor Bar Elasa.)

Rebbi turned around and saw Bar Kafra laughing. Now I will not recognize you as an elder, a Sage. Therefore, Rebbi did not ordain (give Semichah to) to Bar Kafra.

They wished to excommunicate R. Meir (as he disagreed with the Chachamim over a matter of Halachah. Rav Chaim Kanievski explains that it is referring to his disagreement with the Nasi, Rabban Shimon ben Gamliel, as detailed in Talmud Bavli, Maseches Horayos 13b). He responded - I will not listen to you until you tell me who you are excommunicating, why and for which of the 24 known reasons you are doing this. (One who does not know the laws of excommunication may not excommunicate.)

They wished to excommunicate R. Eliezer (in the story of the Chachinai, as detailed below, for disagreeing with the majority opinion). They asked, "Who will go and inform him of this?"

R. Akiva volunteered. When he came to R. Eliezer, R. Akiva said, "Rebbi, your friends are excommunicating you."

R. Eliezer took him outside and said, "Oh carob tree, if the Halachah is like the Chachamim, uproot yourself!" The tree did not become uprooted. "If the Halachah is like me, uproot yourself!" The tree became uprooted. "If the Halachah is like the Chachamim, let the carob return to its place". The tree did not return. "If the Halachah is like me, let the carob return to its place!" The tree returned.

R. Chaninah: Since the Torah was given, we follow the opinion of the majority.

Question: Did R. Eliezer not know this?

Answer: He was upset because they burned his Tahor food in front of him (showing that they ruled that they were Tameh).

The Mishnah in Maseches Keilim teaches: If they sliced up a Tameh earthenware oven and inserted sand in between each slice, R. Eliezer says that the oven is Tahor and the Chachamim say that it is Tameh. This is called the Chachinai oven.

R. Yirmiyah: A great trouble occurred on that day - wherever R. Eliezer looked, the crops became ruined. Also, even in the same wheat stalk, one half was ruined and the other half was not; and the walls of the Study Hall were leaning (out of respect for R. Eliezer).

R. Yehoshua: If the friends are disagreeing, why should it interest you? A Heavenly voice came out and declared, "The Halacha is like my son Eliezer". R. Yehoshua responded, "It [the Torah] is not in the heavens!" (i.e. Hash-m gave over the power of Halachic decision-making to the Sages.)

R. Krispai/ R. Yochanan quoting Rebbi: If someone would tell me that this is the way that R. Eliezer learned (in other laws, but not in the case of the oven, since the Halachah was already ruled to be like the Chachamim), I would cite him in a Mishnah (despite the fact that they excommunicated him). However, other Tanaim have taught the opposite of this.

Once, R. Eliezer was walking in the marketplace and he saw a woman emptying out garbage from her house. She threw it and it fell on R. Eliezer's head. He said, "It appears that today, the friends are releasing my excommunication", as the Pasuk states (Tehilim 113, 7), "...from the garbage dump He will raise the impoverished".

R. Yehoshua ben Levi summoned a certain person three times but he did not come.

He sent a message that if there was still excommunication nowadays, I would excommunicate this man; as there are 24 reasons for excommunicating a person and this is one of them, as the Pasuk states (Ezra 10, 8), "...if anyone does not come within three days, according to the counsel of the officers and the elders, all of his property will be destroyed and he will be separated from the congregation of the exile".

R. Yitzchak bei R. Elazar: Many of these 24 reasons are scattered throughout Mishnah...

The Mishnah in Maseches Taanis teaches: Shimon ben Shetach sent a message to Choni Hame'agel - You should be excommunicated, as if the decree now would be the same as the decree at the time of Eliyahu, you would have brought many to profane Hash-m's name and whoever brings the many to profane Hash-m's name must be excommunicated.

The Mishnah in Maseches Rosh Hashanah: Rabban Gamliel sent a message (to R. Akiva, who had prevented witnesses from coming to Yerushalayim when there was a surplus of 40 pairs that were not needed to be able to declare the new moon) - If you prevent them, you will cause them to stumble in the future (as next time they will not come even if they are needed). You have therefore prevented the many from performing a Mitzvah and whoever does so must be excommunicated.

Beraisa (R. Yosi): Todos of Rome accustomed the people of Rome to eat Mekulas kids on the nights of Pesach (thereby mimicking the Korban Pesach). The Chachamim sent a message saying, "If you would not be Todos, would we not excommunicate you?!"

What was so special about Todos? He financially supported the Rabbanan.

The message continued: You have brought the many to eat consecrated animals outside of the Temple and whoever does this must be excommunicated!