If the narrator is not named, as in expressions such as "so-and-so informed me," or "a shaykh," "a man," "some of them," "the son of so-and-so," or "a thiqa," this is al-mubham.1
An unnamed narrator may be identified by his name appearing through another route of transmission. The scholars have devoted whole works to this, called al-Mubhamāt.
Such a narration is also a form of mursal,2 and its ruling is that of the mursal among the fuqahāʾ and the uṣūliyyūn, indeed, among the early scholars in general. The later scholars, however, hold that it is muttaṣil, but with an unknown narrator in the chain.
Mubham: literally, vague or unspecified. The distinction from muhmal is that in muhmal the narrator's name is given but is ambiguous between two persons of the same name; in mubham the name is not given at all. [tr.] ↩
Mursal has two senses: (1) any case where a narrator is dropped from the chain, at any point; and (2) specifically, where the Companion is dropped. [tr.] ↩
Scholars differ on the precise definition of al-munqaṭiʿ; Ibn ʿAbd al-Barr makes it the broadest category, while for the mutaqaddimūn and the fuqahāʾ it is identical with al-mursal.
When a narrator's solitary transmission is suspected, others' parallel narrations are mutābaʿa or shāhid; the pursuit of these is al-iʿtibār.
Al-Shāfiʿī accepts the mursal under three conditions; some Shāfiʿīs treat the third as one of the four corroborating supports, leaving two conditions.
A ḥadīth in which a narrator has been replaced with another, whether one narrator, several, or even the entire chain, is al-maqlūb (literally, that which has been inverted).
