In a vow a person makes a thing forbidden to himself as though it were a sacred thing or a thing forbidden by a previous vow or by another person’s vow (204:1-3; see 209:1). Making a thing forbidden to oneself as though it were a thing that the Torah forbids is not a vow (because it is not in the vower’s power to make it forbidden), but a person who does so should be reprimanded and requires release (see Ch.16c) to discourage him from swearing casually (205:1; see 212:1). A person may make anything forbidden to himself or make his property forbidden to others, but he may not forbid someone else’s property to anyone (see 209:1;225:1;235:6). On making his share in jointly owned property forbidden to the other owners or to someone else see 226:1-3. A community may punish transgressors by declaring their food and drink forbidden, but opinions differ as to whether an individual may punish himself in this way (205:2). On vows using the term CHEREM see 1:11;208:2;224:1;228:8;229:8;232:18.
An oath is a promise to do or not do something or a claim that a statement is true or false. It need not involve any mention of a Divine name and may be sworn in any language (237:1). For examples of wordings that imply an oath see 212:1;237:3-12;239:2. If a person uses a wording which he thinks implies an oath he should be reprimanded and released from it to discourage him from swearing casually (237:6). A person may swear by including himself in another person’s oath even if that person is a minor or a non-Jew (236:2; 237:2;239:10), and may extend the scope of an oath to additional things (239:9). It is forbidden to swear a false “oath of expression” about a past or future event, but a person who does so is not punished if he swore to fulfill a commandment or to perform an improper action, or if he swore about a future event that is not under his control (236:1-3). It is forbidden to swear a “vain oath” about something that is patently true or patently false or impossible; see 236:4-5.
A person should avoid he may make vows or oaths, but he may make them in times of distress, and making them to encourage his observance of commandments may even be praiseworthy. If a person makes a vow (except for a religious purpose) being released from it (see Ch.10c) is better than keeping it, but if he makes an oath keeping it is preferable, and in either case it should be fulfilled (or annulled) promptly (203:1-7). An oath to do something must be fulfilled at the first opportunity (219:2;232:12). On oaths to do something at or by a specific time see also 228:41. If a time period was specified an oath or vow becomes void when the period is over (231:1), but if no period was specified it is perpetual (219:3). On the definitions of the time periods used in oaths or vows see 220:1-23;228:48.
Four types of vows do not require release: “Vows of insistence” made to emphasize a position taken in a negotiation, “vows of exaggeration” made to dramatize a statement, “vows of forgetfulness” in support of a statement that was made in ignorance of the facts, and “vows of compulsion” that cannot be fulfilled because of factors that would have been difficult to circumvent (232:1-12,16-17). However, a person should not make such vows unless he intends to keep them (232:13). On the corresponding types of oaths see 239:1,16-17. An oath or vow sworn under duress must be kept if it cannot be evaded (see 232:14-15;239:1).
Shulchan Aruch, Copyright (c) 2000 ProjectGenesis, Inc.