Lavan said to Yaakov, “How could you do this? You tricked me, carrying away my daughters as though they were prisoners of war.” (Bereshith 31:26)
Our Sages derive from this verse that deception is considered a type of theft1. Although people tend to think of tricking another as a minor offense, especially compared to an act as blatant as theft, just the opposite is true. Of the seven types of thieves, the worst of them is the one who tricks others.2 (In the case of Yaakov, since he had been cheated numerous times by Lavan, his actions were justified.)3 Since instances of deception are often found in business settings, a storekeeper should always be on guard for possible halachic problems. Some common problems include hiding defects in merchandise,4 listing the price of an item as higher than it is in order to reduce the price when he puts it on sale,5 and selling some inferior fruit together with better fruit.6 All of these practices are aimed at misleading the customer into thinking that he is getting a better deal than he really is, and are therefore forbidden.
Nevertheless, not everything that may appear to be deception is forbidden. Thus, in a place where mixing wine with water is the accepted custom, one is permitted to do so.7 It is also permitted to open a negotiation with a price that is higher that the actual value of the object being sold, allowing the customer to argue down the price.8
Even someone who does not involve himself in business dealings can come across instances of deception. For example, it is forbidden to bring an empty flask of oil to a mourner’s home, in order to give the mourner the impression that oil actually was brought for him. Since the halachah forbids a mourner to anoint himself with oil, it is clear that he will not accept the oil. Therefore the visitor is creating the false impression that he intends to honor him.9 It is also forbidden to act in a friendly manner toward someone whom one hates.10
1 Yirayim Vol. I, mitzvah 124.
2 Tosefta Bava Kama 7:3.
3 See the article, “Insider Trading,” (page 204) on Bereshith 30:32.
4 Shulchan Aruch, Choshen Mishpat 228:6.
5 Niv Sefathayim p. 104.
6 Choshen Mishpat 228:10.
7 Ibid., 228:13.
8 Niv Sefathayim p. 104.
9 Choshen Mishpat 228:7.
10 Orach Mesharim 24:8.
Text Copyright © 2008 by Rabbi Daniel Travis and Torah.org