The Torah commands in Parashat Kedoshim (Vayikra 19:11), “Lo Tignobu,” establishing the prohibition against stealing money. One violates this prohibition by stealing a value of at least Shaveh Peruta (the smallest unit of currency), from either a Jew or non-Jew, and from either an adult or a minor. This prohibition of course applies at all times, in all places, and to both males and females. One may not steal money even with the intention of returning it, such as if one wishes to play a joke on his friend and take something of his without his knowing. The Sefer Ha’hinuch writes that it is forbidden to purchase stolen goods, as one who does is supporting criminal activity. This command includes also the prohibition of “Genebat Da’at” (literally, “theft of the mind”) – misleading someone. One example, discussed by the Gemara in Masechet Hulin (94), is selling non-kosher meat to a gentile without informing him that the meat is non-kosher. A gentile who receives meat from a Jew naturally assumes that the meat is kosher, and thus thinks that it is higher quality. Therefore, a Jew who sells a gentile non-kosher meat – such as if a mistake was made in the slaughtering, and thus the meat is forbidden for consumption – must inform the gentile that the meat is non-kosher, so he knows precisely what kind of meat he receives, and is not misled into thinking he receives kosher meat. Another example is a host who tells his guest that he is opening a new barrel of wine in his honor, when in truth he would have opened it even if the guest was not present (such as if it would soon spoil). The guest would feel flattered by such a gesture, and would decide that he needs to reciprocate the goodwill shown to him – when in truth the host did not do anything special in his honor. The prohibition of “Genebat Da’at” forbids misleading a guest in this way. Similarly, it is forbidden to extend to somebody an invitation which he knows that the person cannot accept. For example, if one knows that his friend is traveling the next week, it is forbidden for him to approach the friend and invite him for a Shabbat meal, pretending that he does not know that the friend will be away. The friend will wrongly think that he received a sincere invitation, and will feel a need to reciprocate. This kind of deception is forbidden by force of the prohibition of “Genebat Da’at.” It goes without saying that one may not sell his fellow merchandise without disclosing defects, or misrepresent merchandise as newer or higher quality than it really is. The Gemara observes that when it comes to financial dealings, people are prone to justifying dishonesty, because of the human being’s natural lust for money. Therefore, whenever any sort of questionable circumstance arises, it is vitally important to consult with a Rabbi or an objective third party for guidance, as one’s own judgment will, almost invariably, be biased in his own favor, and he thus runs the risk of violating the grave prohibition of theft.