- A מומחה לרבים can judge cases himself
A Baraisa states that monetary cases are judged by three judges, ואם היה מומחה לרבים – but if he was a publicly renowned expert, דן אפילו יחידי – he may judge them even alone [this refers to loan disputes, and this Tanna holds they are not included in the Torah’s requirement for three judges]. Rav Nachman said: כגון אנא דן דיני ממונות ביחידי – Someone like me may judge monetary cases alone, and Rebbe Chiya said the same. The Gemara asks if they meant “like me,” דגמירנא וסבירנא – who has learned the laws from his teachers, and can analyze and apply it, ונקיטנא רשותא – and additionally received authorization from the Reish Gelusa to judge דיני ממונות, but without this permit his ruling would be invalid? Or can a מומחה לרבים rule alone even without such authorization? The Gemara quotes an incident in which Mar Zutra brei d’Rav Nachman ruled a monetary case incorrectly, and asked Rav Yosef if he had to compensate the losing party. Rav Yosef told him that if they originally accepted him unconditionally, he is exempt, but otherwise he must pay. We see that despite his not having the Reish Gelusa’s permit (which would have exempted him regardless), his ruling was nonetheless valid.
- The relative effectiveness of receiving רשות in Eretz Yisroel vs. Bavel (הכא שבט והתם מחוקק)
After establishing that one who receives רשות from the Reish Gelusa is exempt from paying for mistaken rulings, the Gemara says it is clear that רשות given in Bavel is effective for Bavel, and רשות given in Eretz Yisroel (by the Nasi) is effective for Eretz Yisroel. Furthermore, רשות in Bavel is definitely effective to exempt its recipient for rulings in Eretz Yisroel as well, דהכא שבט והתם מחוקק – because the leader here in Bavel is called a rod, while the leader there in Eretz Yisroel is called a mere legislator, as a Baraisa teaches: "לא יסור שבט מיהודה" – the rod shall not depart from Yehudah, refers to the Reish Gelusas in Bavel, שרודין את ישראל בשבט – who rule over Yisroel with a rod. "ומחקק מבין רגליו" – Nor a scholar from among his descendants, refers to Hillel’s grandchildren, שמלמדין תורה ברבים – who teach Torah in public. The Gemara proves that authorization received in Eretz Yisroel is not effective for Bavel. The Gemara describes Rebbe Chiya’s requesting רשות from Rebbe for Rabba bar Chanah. He asked: יורה – can he rule cases involving prohibitions? Rebbe answered: יורה – he may rule them. He asked: ידין – may he judge monetary cases? Rebbe answered: ידין – he may judge them.
- רשות is required to pasken איסור והיתר because of the misinterpreted psak of מי ביצים
The Gemara asks why authorization is necessary to pasken cases involving prohibitions ("יורה") if the person knows the laws. It answers, because of the following story: Rebbe once traveled to a certain place and saw the people kneading dough in tamei utensils. When he questioned them, they explained that a talmid had once taught them: מי בצעים אין מכשירין – marsh waters do not prepare food to contract tumah, and they prepared food with such water. In truth, he had told them מי ביצים – the liquid of eggs is not machshir foods for tumah (since it is not one of the seven liquids which do), but they thought he said "מי בצעים" – marsh water, which actually is machshir foods like ordinary water. They further misunderstood a Mishnah, which disqualifies marsh waters to be used for מי חטאת, thinking it is also not machshir foods. This is incorrect, because its disqualification for מי חטאת is simply that it lacks the requirement of מים חיים – spring water. At that time, they decreed: תלמיד אל יורה אלא אם כן נוטל רשות מרבו – a student may not pasken unless he obtains authorization from his Rebbe.