There is a Rabbinic ordinance that allows a person who suspects that his business partner or his employee has cheated him, or has made an error in calculating what is owed to him, to demand that his partner or his worker take an oath attesting to the veracity of the accounts. This is true even if the person has no evidence or witnesses to support his claim (see the Mishna, Shevu’ot 7:8). The Rambam explains the reasoning behind this rule, by arguing that people who are responsible for other people’s money often rationalize to themselves that they are allowed to take a little more than agreed, since they work so hard, and the profits of the business are to their credit. Thus, forcing them to take an oath that all their transactions are above board will help ensure that they will be particularly careful with their partner’s or employer’s money (see Rambam, Hilkhot Shutfim 9:1).
The Mishna on our daf teaches that this rule also applies to a wife who works in her husband’s store or is put in charge of his investments. Rabbi Eliezer extends this even to everyday household tasks. If the husband suspects that she is taking dough or wool that she is working with for herself, he can demand that she take an oath that she has not taken what does not belong to her.
The Gemara explains that Rabbi Eliezer’s position is rejected by the other Sages because ein adam dar im nahash be-kefifah – a person cannot live together with a snake in a basket. This concept is explained by the Talmud Yerushalmi to mean that there cannot possibly be shalom bayit – peace in the house – if the husband is so concerned with the ownership of every small item, and any normal wife will refuse to live in such a situation. The Yerushalmi explains that this extends also to situations where, for example, the wife inadvertently breaks dishes in the house, where it is completely inappropriate to discuss whether she has the obligations of a shomer sakhar (a paid watchman, who has a higher level of responsibility) or a shomer hinam (a volunteer watchman who has a lower lever of responsibility) rather she is free of any obligation – because otherwise it would be an impossible situation at home.