In the Mishna (81b) Rabbi Yehuda uses the term ba-meh devarim amurim – “in what case is this statement said” – to limit the applicability of a given rule to just one case. In an attempt to clarify the discussion in the Mishna, the Gemara brings Rabbi Yehoshua ben Levi who teaches that whenever Rabbi Yehuda uses that expression in the Mishnah, he is not arguing with the previous statement, rather he is explaining it.
The Gemara then quotes a number of Mishnayot where this expression is used in order to examine Rabbi Yehoshua ben Levi’s statement.
One example is a Mishna that appears in Massekhet Sanhedrin (24b) that lists people who will not be accepted as witnesses in a Jewish court, because they are involved in monetary shenanigans that are forbidden by the Sages. These people include dice players, money lenders who take interest, people who gamble on pigeon races, and those who market produce from the Sabbatical year. Rabbi Yehuda says: ba-meh devarim amurim – “in what case is this statement said ” – when this is their livelihood. If a person has another occupation and participates in these activities only occasionally, then he still could be trusted as a witness in court.
Unlike modern courtrooms where witnesses are asked to swear prior to their testimony in order to ensure that they will tell the truth, a Jewish courtroom believes that every witness who is called to testify will tell the truth. Nevertheless, there are several types of people, enumerated in the Mishnayot of Massekhet Sanhedrin, who cannot testify. Close relatives, for example, cannot testify, no matter how upstanding and honest we know them to be. There are also people whose behavior does not allow the court to accept them. Among them are people who have committed sins that put them in the Biblical category of a rasha – an evil person – who cannot be trusted. While the people discussed in this Mishna have not done anything that the Torah forbids, nevertheless, their participation in activities that show them to be susceptible to the influence of monetary gain makes us fear that they could be bribed or similarly influenced to change their testimony.