Aside from Hol HaMoed and aveilut (mourning), this perek discusses situations of nidduy – bans – a type of excommunication.
Although we may have thought that formal bans could only be meted out by a formal court system, Rabbi Shmuel bar Nahmani relates a story about one of the maids who worked in the home of Rabbi Yehuda HaNasi whose ban was accepted by the community of scholars. Once, this particular maid saw a person who was beating his adult child. Her immediate – and vocal – reaction was that this person should be banned, since he was putting a “stumbling block” before his son (see 19:14), who would likely try to defend himself by hitting back (see Shmot 21:15). The ban was accepted, and according to the Gemara, remained in force for three years.
Although her reasoning was certainly correct, why did it take the Sages three years to undo the ban that Rebbi’s maid had declared?
Rabbeinu Yehonatan suggests that the crucial question that needs to be asked when discussing the removal of a ban is whether the individual recognizes the inappropriateness of his actions and accepts that such behavior should not be repeated. Until such time as that point is clarified, the person will remain excommunicated. The Rosh says that in order for a ban to be lifted we need those people who convene to remove it to be greater than the person who declared it in the first place. Rebbi’s maid was known to be a woman of unique intelligence and was truly God-fearing, to the extent that it was difficult to find someone with her qualities who could lift the ban. It should be noted that we find “the maid of Rabbi Yehuda HaNasi” mentioned in other contexts in the Gemara. In one case she is quoted offering interpretations to difficult words whose meaning escaped the Sages, explaining that these were words that she was familiar with from listening to the conversation in the home of her master.