A vow may be binding even if its wording is incomplete or ambiguous; see 206:1-4;207:1;208:1-2;216:7. In doubtful cases release is required, and it is also required if a vow is made using the wording of an oath or vice versa; see 206:5 and 239:11. On the applicability of a vow after the thing that was made forbidden has changed its state or its ownership see 216:1-12 and 223:3-4.
The terms used in an oath or vow are interpreted in accordance with common usage; for examples see 215:6;217:1-48;239:1. The scope of the class of things (or persons) included in an oath or vow is defined in accordance with the swearer’s intentions if they can be deduced; for examples see 218:1-6; 219:1-2;221:1-14;222:1;223:1-2;224:1;226:1;227:1-3;228:49;238:1-3,7-15,23.
An oath or vow may be made conditionally (see 213:3;220:15;232:19;239:1), but the condition must not conflict with the Halacha (see 222:1). A person who breaks an oath or vow should keep it for at least an equal period of time (but at most for 30 days) before being released from it, but if keeping it would be a hardship, release can be granted immediately; see 208:2-5.
An oath or vow is binding only if it is made verbally and intentionally (see 210:1;239:1); but a custom has the force of an oath or vow and requires release (214:1). An oath or vow made in a dream requires release; see 210:2. A person who makes an oath or vow may retract it provided he does so immediately and verbally (210:3). On advance stipulations that oaths or vows will not take effect see 211:1-4.
Vows can apply even to things that do not yet exist (204:4), but not to insubstantial things such as speech (though such vows require release) unless they involve observance of a commandment (213:1-2). Oaths can apply even to insubstantial things (239:3). Vows that interfere with the observance of a positive commandment or the fulfillment of an oath are usually valid (see 215:1-5;227:3). On vows that involve things that are already forbidden either by a commandment or because of an oath see 215:5-6;228:15;238:18-19. On contradictory or redundant oaths or vows see 238:16-17,21-22;239:12-15.
A person is punished for swearing to violate a commandment and such an oath must not be kept (see 236:5;238:5;239:4-8). If a person swears to perform a positive commandment the oath is ineffective (see 238:4), but if he swears not to violate a negative commandment and does violate it he is punished also for violation of the oath. If a person swears to perform actions which include violations of negative commandments he must not violate them, but if he swears not to perform actions which include positive commandments he need not perform them (see 236:5;238:6;239:4).
Shulchan Aruch, Copyright (c) 2000 ProjectGenesis, Inc.