- זקן ממרא if Sanhedrin’s ruling is not מפי השמועה, or the זקן ממרא’s is
Rav Kahana says that if the זקן ממרא quotes his ruling מפי השמועה – from a tradition he heard from his teachers, and the Sanhedrin quote their ruling מפי השמועה as well, or he said "כך הוא בעיני" – this is what appears in my eyes (i.e., his personal decision), and the Sanhedrin’s ruling is also from their reasoning, and certainly if his ruling is מפי השמועה and theirs is from their reasoning, he is not killed as a זקן ממרא, unless he is ruling based on his own reasoning, and ignores the Sanhedrin’s ruling which is מפי השמועה. This is why עקביא בן מהללאל was not killed for not accepting Sanhedrin’s rulings, because he had received his rulings מפי השמועה. Rebbe Elazar disagrees and says that even if the זקן ממרא’s ruling was מפי השמועה, and Sanhedrin’s was based on their own reasoning, he is killed, כדי שלא ירבו מחלוקות בישראל – so that disputes should not proliferate in Yisroel. Still, עקביא בן מהללאל was not killed, because he did not rule for his position to be followed practically. A Baraisa teaches that Sanhedrin cannot pardon a זקן ממרא, כדי שלא ירבו מחלוקת בישראל, proving Rebbe Elazar’s opinion.
- Disputes were initially resolved by Sanhedrin
In a Baraisa, Rebbe Yose said that initially, disputes were not numerous in Yisroel. Whenever a local Beis Din had not heard a ruling on any matter, they would ask the Beis Din of the nearby city, and if they too had not heard the answer, they would come to the Beis Din at the entrance of הר הבית, then the Beis Din at the entrance of the עזרה, and finally they would all come to the Sanhedrin which sat in the לשכת הגזית every day from when the morning תמיד is brought until the afternoon תמיד is brought (on Shabbos and Yom Tov, they sat in the חיל). If they had heard the answer, they related it, but if not, עומדין למנין – they took a vote and followed the majority, and so disputes were resolved. However, once the students of שמאי and הלל increased, שלא שמשו כל צרכן – who did not sufficiently attend to their teachers, רבו מחלוקת בישראל – disputes increased in Yisroel, ונעשית תורה כשתי תורות – and the Torah became like two Torahs because of the numerous differences in practice.
- A זקן ממרא who maintains that תפלין require five compartments
The next Mishnah states that there is a greater stringency in the סופרים's words compared to the Torah’s words regarding זקן ממרא. If a זקן ממרא says there is no mitzvah of tefillin, he is exempt, because it is obviously false, and not a legitimate ruling. However, if he says tefillin (של ראש) require five compartments instead of four, להוסיף על דברי סופרים – to add onto the סופרים’s words, he is liable.
Rebbe Oshaya says that a זקן ממרא is only liable for disputing a matter whose fundamental element is written in the Torah, its interpretation is taught by the סופרים (like Rebbe Yehudah said on Daf 87a), ויש בו להוסיף – and it is possible to add onto its required elements, ואם הוסיף גורע – and if one adds to the number he detracts from the mitzvah’s fulfillment. This is only possible with tefillin, where adding a fifth compartment violates בל תוסיף – you shall not add (to any mitzvah) and invalidates the tefillin. Although regarding לולב and ציצית, adding another element does not retract from the mitzvah if the mitzvah’s components are not required to be bound together, tefillin are invalidated by adding a fifth compartment, because the outer compartments must be exposed to the air.