Being Careful With Other People's Money

When is taking without permission permitted?

The gemara records a story in which the sharecropper of Mari Bar Isak took fruit to some of Amoraim while Mari Bar Isak was away. Some of the Amoraim ate the fruits, while Rav Ashi did not. Rashi explains that Rav Ashi was concerned that the sharecropper was taking Mari Bar Isak’s fruit without permission and didn’t want to benefit from stolen goods. If so, what were the other Amoraim thinking? Tosfot (Bava Metsia 22a s.v. mar) explains that they assumed that the sharecropper was giving his own fruits. Then Tosfot adds that it would not have been a correct justification if the other Amoraim assumed that the sharecropper took Mari’s fruits, but once Mari would find out about it, he would be okay with it. Tosfot proves that an expression of intent isn’t effective for past events from the topic of yeush shelo medaat, assuming someone would relinquish ownership if an item is lost.

Tosfot’s opinion is quoted by the Shulchan Aruch and accordingly it would be prohibited to take someone else’s property even if one assumes that they would be agreeable when he finds out. Even though the Shach (C.M. 358) disagrees, the poskim (Kitzur Shulchan Aruch 182:13, Aruch HaShulchan 358:8) follow the opinion of Tosfot. Nonetheless, Rabbi Bodner (Halachos Of Other People’s Money p. 26) quotes poskim who say that if a friend or relative have allowed you to take a particular item in the past with regularity it would permitted to take it without consent.

General Rules

1. Rav Yehudah in Bava Basra (165a) informs us that most people steal, a minority engage in illicit sexual activity, and everyone says Avak Loshon Hara. The Rishonim explain that the Gemara is not referring to outright stealing such as shoplifting but more subtle forms of stealing that afflict our interactions as buyers, employers, landlords, etc. A person who keeps stolen money is both subject to severe punishments for stealing and also sets himself up to one day become a victim. Thus, it is incumbent upon everyone to be aware of the Halachos of other people's money.
2. Stealing is prohibited even if it's less than a Prutah, which is a few cents. Despite the fact that anything less than a Prutah is not considered to be money, we nonetheless Pasken that for Torah prohibitions חצי שיעור, or anything less than the set amount prescribed, is still forbidden from the Torah. However, it is not considered to be stealing if no one will object to you taking the item of negligible value. Nonetheless it is preferable to receive permission first.
3. Stealing is prohibited even if one is taking a friend's possession as a practical joke or to annoy him, even if he has every intention of returning the item after the joke has run its course.
4. Even if one takes an item from his friend to benefit his friend it is prohibited. For instance, one cannot take an old garment from his friend with the intention of buying him a new one. One cannot also take away something from someone to teach him a lesson. The one exception to this rule is a teacher who is able to confiscate an item to discipline the class. While the teacher should return the item, if the teacher feels that discipline will only be achieved with the destruction of the item he may do so.

Benefiting from stolen goods

1. It is forbidden to buy something that a thief stole, whether the thief is Jewish or non-Jewish.