an oath that one may choose to break or keep; nor is any expiation due for this, by the agreement of the Muslims. In their established terminology, jurists do not call this an oath or an act of swearing. Some people, however, say, “I swore an oath invoking divorce,” when they mean that they pronounced a divorce.

As for the “oath formula,” this is when a person says: “Divorce shall be binding upon me: I will certainly do such-and-such,” or, “I will not do such-and-such.” He thus invokes divorce in an oath to urge himself or someone else to act, to prevent himself or someone else from acting, or to affirm or deny the truth of a report.

This falls under questions concerning both divorce and oaths. It is an oath by the agreement of scholars of the Arabic language, since it takes the form of an oath. It is also an oath in the terminology of the jurists: they have not disputed its designation as an oath, but they have disputed its ruling. Some jurists gave precedence to its character as a divorce pronouncement and therefore held that divorce takes effect if he breaks the oath. Others gave precedence to its character as an oath and therefore did not hold that divorce takes effect. Rather, they said that he must offer expiation for breaking an oath, or that nothing is required of him at all.

They likewise differed concerning someone who swears an oath by making a vow, saying: “If I do such-and-such, I must perform Hajj, fast for a month, or give my wealth in charity.” However, statements concerning this kind of oath are widely reported from the early generations, including the Companions and others. They said that these are oaths for which the expiation prescribed for breaking an oath suffices, since such oaths occurred frequently in the time of the Companions. By contrast, discussion of oaths invoking divorce is known only from the Successors and those after them, who differed over it, holding the two positions mentioned above.