This brings to mind the story about Rabbi Shimon Ben Shetach and the donkey:
There was a case in which the students of Rabbi Shimon ben Shetach, one of the greatest Tannaim of all time, tried to find him a new business because he was exceedingly poor. Rabbi Shimon ben Shetach was involved in Linen work. Obviously the linen work was not sufficient for him to make a living. His students urged him to leave this business and instead they would buy him a donkey. This way he would not have to work so hard and at the same time would be able to live comfortably.
They went ahead and bought a donkey from a non-Jew. According to the notes at the bottom of the Talmud Yerushalmi (and we do not know exactly who they are from), he was an Ishmaelite thief so the donkey was not really his to start with. This makes the story even more interesting because of what is about to come. The students discovered a pearl on the donkey and took it to Rabbi Shimon ben Shetach exclaiming that they struck it rich and that from now on he does not have to work anymore. But Rabbi Shimon ben Shetach asked the students: Did the owner of the donkey know that there was a pearl attached to it. They answered “NO”. Rabbi Shimon ben Shetach said to them: “Go give it back!”.