- Second opinion: מדאורייתא, one judge suffices for loans, three were required משום יושבי קרנות
Rav Acha brei d’Rav Ika explains differently why loan disputes require three judges, but not מומחין. He holds that Biblically, even a single judge suffices, as the passuk says: בצדק תשפט עמיתך – with justice “you” shall judge your fellow (written in the singular). Three judges are required Rabbinically, משום יושבי קרנות – because of corner-dwellers who do not know monetary laws. By requiring three judges, it is inevitable that one of them will be sufficiently knowledgeable in דיני ממונות. Although unordained judges are valid Biblically, they are still liable to pay if they judge incorrectly (as opposed to מומחין), because if they would be exempt, it would increase the number of יושבי קרנות who would judge without learning monetary laws. The Gemara explains that the practical difference between this opinion and Rava’s is Shmuel’s ruling, that שנים שדנו דיניהן דין - two judges who ruled on a loan dispute, their decision is a valid decision. Rava, who holds three מומחין are Biblically required (but three הדיוטות were allowed Rabbinically), disagrees with Shmuel.
- The source requiring three judges (אלהים written multiple times)
The Gemara quotes a Baraisa about the source requiring three judges for דיני ממונות. Rebbe Yoshiyah says that the Torah says "אלהים" three times in the pesukim about a שומר חנם swearing in court, teaching a requirement of three judges. Rebbe Yonasan says we do not count the first mention of אלהים, because אין דורשין תחילות – we do not darshen initial descriptions when considering the number of times a term is used, since it is necessary to teach the primary law that a מומחה is required (because "אלהים" implies greatness). Rather, the term אלהים is written superfluously twice, requiring two judges, ואין בית דין שקול – and a Beis Din cannot have an even number of judges (to enable a majority ruling), so an additional judge is required, totaling three. The Gemara explains that even Rebbe Yoshiyah can agree that we do not darshen תחילות but holds that if this first occurrence was not to be counted, the Torah should have written "השופט" – the judge. Since the Torah used the term אלהים, it indicates it should be counted towards the number of judges required.
- Machlokes if a Beis Din requires an odd number of judges
The Gemara wonders why Rebbe Yoshiyah needed three mentions of "אלהים" to teach the requirement of three judges. Does he not agree that we require בית דין נוטה – an uneven court? But a Baraisa teaches that the passuk לנטת אחרי רבים להטת – to decide, according to the majority it shall be decided, teaches: עשה לך בית דין נוטה – make for yourself an uneven court to enable a majority ruling!? The Gemara answers that Rebbe Yoshiyah holds like Rebbe Yehudah, who says the Sanhedrin was composed of seventy judges, an even number, and does not require an uneven court [thus, Rebbe Yoshiyah would allow a Beis Din of four or six judges]. The Gemara objects that Rebbe Yehudah himself only allowed for an even court in the Sanhedrin but requires an uneven court elsewhere. This can be proven from his requiring five judges for the סמיכה of the elders on the פר העלם דבר, which is based on the rule of אין בית דין שקול!? The Gemara concludes that Rebbe Yoshiyah allows for an even court even where Rebbe Yehudah does not. He agrees, however, that "לנטות" requires an uneven court for דיני נפשות – capital cases.