Bais HaVaad on the Parsha, Parshas Dvarim
Rule of Three
August 9, 2024
Excerpted and adapted from a shiur by Dayan Yosef Greenwald
You shall not show favoritism in judgment, small and great alike shall you hear…
Dvarim 1:17
The Rambam (Sefer Hamitzvos Lo Sa’aseh 284, based on Sanhedrin 7b) says this is a mitzvah not to appoint dayanim to a bais din without the requisite knowledge and wisdom to rule. He additionally codifies a mitzvas asei to appoint qualified dayanim in every district.
The classic sfarim note a distinction between a bais din adjudicating dinei mamonos and a rav ruling on matters of issur veheter: The rav applies the halacha to the case at hand, but every case of dinei mamonos is unique, so a new psak must be made for it by the bais din. Three dayanim are involved to ensure the novel psak is correct. A litigant cannot argue in bais din that his rav said he’s right, because unlike in issur veheter, where the psak is only applied, the creation of a psak for dinei mamonos requires that both parties and the dayanim be present together to ensure accuracy.