As for the report of a mastūr—that is, a narrator whose outward conduct is upright while his inner state remains unknown—some of those who had rejected the previous category nevertheless consider it admissible; this is the view of certain Shāfiʿī scholars. The Shaykh said: It would appear that this is in fact the prevailing practice in many ḥadīth collections regarding a number of transmitters from early generations whose era is distant and whose inner condition can no longer be examined.

By contrast, a narrator who is majhūl al-ʿayn (his very person is unknown) may be rejected even by some who accept the mastūr. Once two upright transmitters relate from him and identify him by name, the obscurity concerning his person is removed. Al-Khaṭīb said: Among the ḥadīth scholars a man is deemed unknown when the scholars do not recognize him and his ḥadīth is transmitted through only one route; the least that removes this unknown status is the narration of two well-known transmitters. Ibn ʿAbd al-Barr conveyed a similar definition on behalf of the ḥadīth specialists. The Shaykh replied to al-Khaṭīb: Al-Bukhārī narrated from Mirdās al-Aslamī, and Muslim from Rabīʿah b. Kaʿb al-Aslamī, even though only one person narrated from each of them. Hence the disagreement on this point is understandable, just like the debate over whether a single act of endorsement suffices; nevertheless, the correct view is what al-Khaṭīb reported, and it is invalid to refute him with the cases of Mirdās and Rabīʿah, for both were well-known Companions, and all the Companions are upright.

Sub-section
The endorsement of reliability issued by a knowledgeable slave or woman is accepted. A transmitter whose identity and uprightness are known—even though his personal name is not—is also relied upon. Likewise, if someone says, “So-and-so and So-and-so, both upright, informed me,” his report is accepted; but if the uprightness of either one is unknown, or he says, “So-and-so or someone else,” the report is not accepted.

Seventh: One who has fallen into disbelief because of his innovation is, by consensus, not relied upon; as for one whose innovation does not amount to disbelief, it has been said