the vesting of clientage in someone other than the emancipator—was a condition not found in Allah’s Book. Consider the stipulated matter, whether it is [an act] or a legal ruling. If Allah has permitted it, it may be stipulated and becomes binding; if Allah has not permitted it, it may not be stipulated. Thus, if a man stipulates that he will not travel with his wife, this stipulated matter is found in Allah’s Book, because Allah’s Book permits him not to travel with her. By stipulating that there be no travel, he has therefore stipulated a permissible matter found in Allah’s Book.

The purport of the hadith, then, is that a stipulated matter is invalid when it is not among the permissible acts. Alternatively, “not in Allah’s Book” may mean that its negation is [in] Allah’s Book, as he said: “There will be people who tell you things that neither you nor your forefathers knew”—meaning, things whose contrary you know; otherwise, there are many things one does not know.

We then say: The Prophet—may Allah bless him and grant him peace—cannot have meant that contracts and conditions not permitted by the Lawgiver are invalid in the sense that they entail no legal consequence at all—neither obligation nor prohibition—for such an understanding would contradict the Book and the Sunnah. Rather, prohibited contracts and conditions may entail legal rulings. Allah prohibited the act of zihār in His Book itself and called it “an objectionable statement and a falsehood” [al-Mujādilah: 2]. Yet He made it entail expiation for anyone who returns; as for one who does not return, the intended consequence of the prohibition—abstaining from intercourse or abandoning the contract—was realized in his case. The same applies to vows: “The Prophet—may Allah bless him and grant him peace—forbade vows,” as is established from him in the hadiths of Abū Hurayrah and Ibn Umar. He said, “They bring no good.” Yet he required a vow to be fulfilled when it involved obedience, saying—may Allah bless him and grant him peace—“Whoever vows