In our discussion of geneivas daas there is another important heter
(leniency) in the Gemara, (Chullin 94a). Rav Safra and Rava bumped into Mar
Zutra in the street. Mar Zutra thought that they had come out to meet him,
and he said why did you burden yourselves to come out to meet me? Rav Safra
answered that in truth they did not come out to meet him, however, had they
known that he was coming, they would indeed have done so. Rava argued with
Rav Safra that there was no need to inform Mar Zutra because Mar Zutra
‘deceived himself’ into thinking that they came out to meet him (ie. That
there was no compelling reason for him to believe that they came to visit
him, rather he persuaded himself that this was the case). In such an
instance there is no prohibition of geneivas daas (and telling this to Mar
Zutra disappointed him unnecessarily).
Based on this Gemara, the Shulchan Aruch (Simun 228:6) rules that if a
person deceives himself, there is no prohibition of geneivas daas. Rashi
explains this law by saying that if one doesn’t say or do anything that
suggests that he did something for his fellow, rather he acts normally, and
his fellow imagines that he did it for him, there is no prohibition of
geneivat daat. In fact, we see from the Gemara, that he should not tell him
the truth because it will only cause him pain.
Therefore, one who goes to visit someone in the hospital, and he sees
someone else he knows there, and this patient thinks the visitor came for
him, he should not tell him the truth, and indeed it is forbidden to do so
(this is presuming that the patient had no reason to assume that the person
came specifically to visit him). However, it is forbidden to imply to him
that he came specifically to visit him.
1.This article is based on a talk given by Rabbi David Genish, Shlita, Rabbi
of Kehillat Meam Loez.