the school’s doctrine, for a party stipulating a condition has no authority to permit what Allah has forbidden or forbid what Allah has permitted; in that case, his condition would nullify Allah’s ruling. Nor may he waive what Allah has made obligatory. Rather, he may use a condition only to make obligatory what would not be obligatory without it. Thus, the purpose of conditions is to make obligatory something that was previously neither obligatory nor forbidden. The fact that the Law does not itself impose an obligation does not mean that it rules out such an obligation, such that the stipulated condition would contradict the Sacred Law. Every valid condition must therefore make obligatory something that was not previously obligatory. Indeed, when two people enter into a sale, each becomes obligated toward the other to deliver something he had not previously been required to deliver. Each is also permitted something that had not previously been permitted to him, and each is forbidden something that had not previously been forbidden to him. The same applies to the parties to a lease and to the spouses in a marriage contract. Likewise, if a quality is stipulated in the item sold, collateral is required, or the woman stipulates an amount exceeding the customary dowry of a woman of her standing, then by that condition something becomes obligatory, forbidden, or permissible that was not so before.

This is precisely what misled those who held that the basic rule is that conditions are invalid. They argued: “A condition must either permit what is forbidden, forbid what is lawful, impose what was not obligatory, or waive what is obligatory; and none of that is permissible without authorization from the Lawgiver.” This misconception was presented to some people until they imagined this hadith to be self-contradictory. It is not. Rather, whatever is forbidden in the absence of a condition cannot be made permissible by a condition, such as usury, sexual relations with a slave woman owned by another, or assigning the bond of clientage to someone other than the emancipator. Allah has forbidden sexual relations except through a marriage contract or ownership of a slave woman. Thus, if a man wished to lend his slave woman to another man for sexual relations, he would not be permitted to do so, unlike lending her to serve him, which is permissible. The same applies to the bond of clientage, for “the Prophet—may Allah bless him and grant him peace—forbade selling or giving away the bond of clientage.” Allah made the bond of clientage analogous to lineage: it is established for the emancipator just as lineage is established for the father. He—may Allah bless him and grant him peace—also said: “Whoever claims descent from anyone other than his father, or attributes his clientage to anyone other than his rightful patrons, incurs the curse of Allah, the angels, and all humankind; never