In the previous article we discussed various forms of deceit and trickery
that constitute stealing. What is the law when money or merchandise is
given in error? Is the person ever permitted to keep the money without
informing the company or individual of his mistake?
The Talmud tells us that deliberately neglecting to return money given in
error is forbidden by three Torah commandments. One of them is the
prohibition not to steal. The other two are commandments relating to the
obligation to return lost objects - money or items given by mistake fall in
the category of lost items that must be returned.
There is much discussion about returning money given in mistake by non-Jews,
which is beyond the scope of this column. However, it is important to
note that it is highly recommended to always adopt an approach that takes
into the consideration that other people will carefully observe view a Jew's
actions in monetary matters. By being scrupulously honest, a Jew brings
about a kiddush Hashem, (a sanctification of G-d's name) whereby people see
the virtuous conduct of the Jewish people. Conversely, being deceitful
brings about a chillul Hashem (a desecration of G-d's name).
Rav Pinchos Bodner shlita tells over the following story that demonstrates
the importance of being honest, and the way we are viewed by the people
Rav Yaakov Kaminetsky zt"l recounted that when he was a Rabbi in
Lithuania before World War 2, he was asked a question by a resident of his
community. The man had purchased stamps from the local post office, and had
received more stamps that he had paid for. For such a poor man, the extra
stamps were no trifle matter. Nonetheless, Rav Kaminetsky suspected that
perhaps the postal clerk was testing the rabbi. This suspicion was
confirmed a short time later when the clerk gave him too much change. The
rabbi returned the extra money. Many years after the Nazis came and
destroyed the community, the rabbi heard that this clerk had saved many
Jews, testifying that he tested everybody to assess their honesty, the only
trustworthy people were the Jews!
This teaches us that in addition to the obligation to be honest and avoid
thievery, a Jew must be extra vigilant to bring about a kiddush Hashem.
 See gemara, Bava Metsia, 26b.
 See Rav Pinchos Bodner, 'Halachos of Other People's Money, p.5-51 for
more on this issue.
 He was one of the leading Rabbanim in the world in the second half of
the 20th century.