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By Rabbi Aron Tendler | Series: | Level:


What practices are included in the prohibition of Geneivas Da’as (literally – stealing someone’s knowledge), the prohibition against misleading others in business and other interpersonal matters?


  1. A. It is forbidden by the Torah to mislead any fellow human being. This includes non-Jewish people. This applies to all interpersonal matters, whether business related or otherwise.

    Included in this prohibition is misleading a buyer to think that certain merchandise is of better quality than it actually is, even if the amount that he is paying is the correct amount for the item being sold. Also, saying or doing something that will lead others to think that you have honored them or done them a favor when this is not so, is included in the prohibition of Geneivas Da’as. (1)

  2. B. Based on the above, a merchant is obligated to inform a potential buyer about any defect that exists in an item that the merchant wishes to sell, if such knowledge may influence the buyer’s decision whether or not to purchase the item. Similarly, a merchant may not claim that an item was made by a certain manufacturer, or in a certain country, if this is not true, despite the fact that he will charge the same price in any case. (2)

  3. C. A salesman may not try to convince a customer to buy something by telling the customer that the price that he is being offered is one that others had offered to pay for this item but had been refused. The salesman may not tell the customer that he (the salesman) is only making a minimal profit on the sale and this is the lowest amount that he could possibly charge.

    In these situations, although the salesman or merchant may have transgressed the Torah prohibition of Geneivas Da’as, the sale can not be declared void by the customer when he finds out that the information provided was misleading. (3)

  4. D. It is forbidden to invite someone for a meal or to an event if the host knows that his friend will not come, and is only inviting the friend so that the friend will think that the host wanted him to come, and will then repay the favor in some manner. On the other hand, if the host knows that his friend will be insulted not to receive an invitation, even if it is known that the friend will not come it is permitted to invite him. (4)
  5. E. If someone is hosting a guest and must open a new bottle of expensive wine for himself, but the guest is under the impression that he did so in honor of the guest, the host is not obligated to correct his guest’s false impression, since he has not done any action that everyone would interpret in this manner. However, if there are people that are under the impression that he has done them a favor or honored them in some manner, and wish to give him a gift because of this, he may not accept it if it is really untrue. Similarly, if an organization or school would like to honor or award someone because they believe that he has attained a certain level of scholarship that he actually has not, he would not be permitted to accept this honor or award. (5)


(1) The Gemara in Chullin (94a-b) states that it is forbidden to mislead people in any way, even a non-Jew. This is also stated as the Halacha in the Rambam (Hilchos Mechira 18:1), and in the Shulchan Oruch (Choshen Mishpat 228:6). The Halachos that we have stated here have been taken directly from the Shulchan Oruch and the SM”A there (9-10).

(2) The SM”A there (7) adds that even when an item has a defect that does not diminish the value of that item, a potential customer must be informed about it. Obviously we are referring to a defect that may influence the customer’s decision whether or not to purchase it. A minor scratch or defect that the average person is not concerned about does not need to be pointed out, as long as the value of the item is not decreased by it.

(3) It can be inferred from the words of the Shulchan Oruch there (16), that if people are particular regarding the country or city in which a particular item was manufactured because certain places have a reputation for producing quality items, the merchant may not mislead his customers in any way, neither verbally nor with action, into thinking that his merchandise is from a particular country when it is not. This is true even if the items from the country with the better reputation are the same price as the items from the other countries.

The Ta”z (Choshen Mishpat 332:4) states that although a merchant may have misled his customers, a customer can not claim that such a sale be voided, unless he expressly stated before purchasing the item that he is buying it only because it was manufactured in a particular place, etc. However, the merchant has transgressed the Torah prohibitions of Geneivas Da’as, besides the prohibitions involved in saying falsehoods.

(4) This is stated in the Shulchan Oruch, Choshen Mishpat (228:6), and the SM”A there (8).

(5) The Gemara and the Shulchan Oruch there state that when people are not misled, but jump to conclusions based on their own mistaken impression, you are not obligated to correct the impression that they have. However, we find in the Yerushalmi (Makos Perek 2 at the end of Halacha 6) that if a person knows only one Masechta (tractate) of the Gemara, yet people want to honor him because they are under the impression that he knows two Masechtos, he must tell them the truth, even though he did nothing to mislead them! How can we reconcile the position of the Yerushalmi, and our Gemara in Chullin? It does not seem reasonable that we should make a distinction between Geneivas Da’as when it comes to knowledge in Torah and other matters!!

It appears that this can be answered in the following two ways:

A – The Yerushami is talking about a situation where the Talmid Chochom is participating in a ceremony honoring him for his “achievement”. His participation creates the impression that what they are assuming is true. Consequently, he is misleading people with his actions, and it is therefore forbidden.

B – It is possible that the Yerushalmi is not concerned about the Geneivas Daas of those that are honoring him, since they are misleading themselves. The problem is that the recipient of the honor is receiving something that he does not deserve, which is forbidden when it is being given mistakenly. In other words, if he would be given a discount in a certain store, for example, based on the assumption that he is more of a scholar than he actually is, he would clearly be forbidden to take it. To do so would be theft. So too here, he should not take this honor being bestowed on him when he is truly not deserving of it.

According to the first reason that we’ve just stated, the problem is that he is misleading those who are giving him the honor. According to the second reason, the problem is that he is accepting something of which he is not deserving, even though there is no Geneivas Daas, since he has done nothing to mislead the others. However, if he receives nothing beneficial because of the erroneous assumption of others, they merely have gratitude for what they think that he has done for them, and does no action at all to give them the impression that they are correct, according to both reasons he would have no obligation to inform them that they are mistaken. It is in this situation that the Gemara and Shulchan Oruch state that you have no obligation to correct your friend’s mistaken impression so that they do not have gratitude for something that you actually haven’t done for them.

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This week’s class is based on a column by Rabbi Tzvi Shpitz, who is an Av Bais Din and Rosh Kollel in the Ramot neighborhood of Jerusalem. His Column originally appears in Hebrew in Toda’ah, a weekly publication in Jerusalem. It has been translated and reprinted here with his permission and approval.

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Please Note: The purpose of this column is to make people aware of Choshen Mishpat situations that can arise at any time, and the Halachic concepts that may be used to resolve them. Each individual situation must be resolved by an objective, competent Bais Din (or Rabbinic Arbitrator) in the presence of all parties involved!