Generally speaking, a person who commits certain kinds of Torah violations is disqualified from serving as a witness. This applies to Torah violations that are punishable by Malkot (lashes) or execution, and also to violations involving money. If a person disregards the Torah’s code of monetary law, then there is reason to suspect that he will not speak truthfully in court, and he is therefore disqualified as a witness.
An exception to this rule is somebody who committed a Torah violation under the mistaken assumption that he was committing a noble act. The classic example of such a situation, as discussed in the Gemara, is the case of Hebra Kadisha members who perform burials on the first day of Yom Tob. Burying on the first day of Yom Tob is certainly forbidden, but Hebra Kadisha members might assume that given the importance which the Torah affords to the immediate burial of a deceased person, they actually perform a Misva by burying on Yom Tob. Therefore, even though this assumption is wrong and misguided, they are nevertheless qualified to serve as witnesses, since they mistakenly perceive their sinful conduct as noble conduct. This Halacha applies even if they continue this wrongful practice after the local Bet Din had placed them under Nidui (excommunication). One might have assumed that once Bet Din condemned their practice of burying on Yom Tob, to the point of issuing a writ of excommunication, subsequent violations would be considered willful, intentional sins that disqualify them from testimony. In truth, however, the Hebra Kadisha members are still qualified as witnesses, because they figure that the Nidui is necessary as atonement, but not an indication that they act wrongly. They might compare their situation to one of a person who experiences a frightening dream on Friday night, who is allowed to fast on Shabbat, but must then observe another fast to atone for having fasted on Shabbat. Similarly, the Hebra Kadisha members might view their Nidui as a means of atonement that they must endure for burying on Yom Tob, even though the burial is warranted. Therefore, they are qualified to serve as witnesses despite the violation they commit.
Another example is a person entrusted with the funds inherited by young orphans, and lends some of the money on interest. Generally, lending on interest renders one disqualified from giving testimony, because, as mentioned earlier, one who commits Torah violations involving money is disqualified as a witness. However, in the case of the administrator entrusted with orphans’ accounts, he mistakenly thinks he performs a Misva by lending the funds on interest and thereby earning money for the young orphans under his charge. Therefore, even though he acts wrongly and commits a Torah violation, he is nevertheless allowed to serve as a witness, since his violations were committed under the assumption that he performs an important Misva.
Summary: A person who commits a Torah violation thinking that he performs a Misva – such as an administrator of young orphans’ funds who lends their money on interest – is allowed to serve as a witness, even if the violation he commits generally renders one disqualified for giving testimony.
