Mutawātir is an appellation given to those ḥadīs̤ only that have always been, from the time of the Prophet, ever afterwards recognised and accepted by every associate of the Prophet, and every learned individual, as authentic and genuine, and to which no one has raised any objection. All learned Muḥammadan divines of every period have declared that the Qurʾān only is the Ḥadīs̤ Mutawātir; but some doctors have declared certain other ḥadīs̤ also to be Mutawātir, the number, however, of such ḥadīs̤ not exceeding five. Such are the traditions that are implicitly believed and ought to be religiously observed.
Mashhūr is a title given to those traditions that, in every age, have been believed to be genuine, by some learned persons. These are the traditions which are found recorded in the best works that treat of them, and, having been generally accepted as genuine, form the nucleus of some of the Muslim doctrines.
K͟habar-i-Aḥad (or ḥadīs̤ related by one person), is an appellation given to traditions that do not possess any of the qualities belonging to the traditions of the first two grades. Opinions of the learned are divided whether or not they can form the basis of any religious doctrine.
Persons who undertook the task of collecting traditions had neither time nor opportunity for examining and investigating all the above particulars, and some of them collected together whatsoever came under their notice, while others collected only those whose narrators were acknowledged to be trustworthy and honest persons, leaving entirely upon their readers the task of investigating and examining all the above-mentioned particulars, as well as of deciding their comparative merits, their genuineness, and the quantum of credit due to them.
There is some difference of opinion as to who first attempted to collect the traditions, and to compile them in a book. Some say ʿAbdu ʾl-Malik ibn Juraij of Makkah, who died A.H. 150, whilst others assert that the collection, which is still extant, by the Imām Mālik, who died A.H. 179, was the first collection. The work by Imām Mālik is still held in very great esteem, and although not generally included among the standard six, it is believed by many to be the source from whence a great portion of their materials are derived.
The following are the Ṣiḥāḥu ʾs-Sittah, or “six correct” books, received by Sunnī Muslims:—
(1) Muḥammad Ismāʿīl al-Buk͟hārī, A.H. 256.
(2) Muslim ibnu ʾl-Ḥajjāj, A.H. 261.
(3) Abū ʿĪsā Muḥammad, at-Tirmiẕī, A.H. 279.
(4) Abū Daʾūd as-Sajistānī, A.H. 275.