Second category: the shaykh authorizes a particular individual with regard to material other than a single specified book, as when he says, “I authorize you to transmit everything I have heard.” The disagreement here is stronger and more widespread, yet the majority of scholars from the various schools allow narration on its basis and consider acting upon it obligatory.

Third category: the shaykh authorizes an unspecified person by a general description, such as, “I authorize the Muslims,” “I authorize anyone,” or “I authorize the people of my time.” Later scholars have differed over this. If the authorization is confined by a more precise qualifier, it is closer to being acceptable. Among those who judged it valid are Qadi Abu al-Tayyib, al-Khatib, Abu ʿAbd Allah Ibn Mandah, Ibn ʿAtab, the hadith master Abu al-ʿAlaʾ, and others. The shaykh (Ibn al-Ṣalāḥ) said, “We have not heard of anyone worthy of emulation who actually transmitted on the basis of such an authorization.” I reply: The plain sense of those who deemed it sound is that narration by means of it is permissible, for that is precisely what its validity entails—what benefit could it have other than enabling narration?

Fourth category: authorizing someone whose identity, or the item authorized, is ambiguous at the outset—for instance, “I authorize you concerning the Sunan,” while the shaykh narrates several works entitled Sunan, or “I authorize Muhammad ibn Khalid al-Dimashqi,” when several individuals share that name. Such an authorization is invalid. However, if he grants authorization to a group who are named in the request or otherwise, yet he does not know their individual identities, lineages, number, or inspect them personally, the authorization is valid, just as their hearing from him in a large session would be valid.

As for saying, “I authorize whomever so-and-so wishes,” or similar wording, it involves both vagueness and suspension; the stronger view is that it is invalid, a position decisively affirmed by Qadi Abu al-Tayyib al-Shafiʿi. Ibn al-Farraʾ the Hanbali and Ibn ʿAmrūs al-Maliki, however, considered it sound. If he were to say, “I authorize whoever desires authorization,” it is equivalent to “I authorize whomever so-and-so wishes,” and even more obscure. Yet if he says, “I authorize whoever wishes to narrate from me,” it is more deserving of acceptance, because it explicitly states the intended purpose.