A solitary report transmitted by an upright narrator (ʿadl) of complete retention (tāmm al-ḍabṭ), with a connected chain, free of any concealed defect (ʿilla) or anomaly (shudhūdh), is al-ṣaḥīḥ li-dhātihi (the sound in itself).1
Nukhbat al-Fikr, p. 24. This is the ḥadīth which is judged ṣaḥīḥ without disagreement among the people of ḥadīth. They may, however, differ over the authenticity of certain ḥadīth, either because they differ as to the presence of these attributes in them, or because they differ as to whether some of these attributes are required, as in the case of the mursal. Muqaddimat Ibn al-Ṣalāḥ, pp. 16–17, as will follow in the discussions to come. It is known, then, that this is the definition of the ṣaḥīḥ that is agreed upon, not of the ṣaḥīḥ in absolute terms; and that it is the definition of the ṣaḥīḥ according to the muḥaddithūn, not according to others. ↩
If the retention (ḍabṭ) is light while the other attributes of ṣaḥīḥ remain present, it is al-ḥasan li-dhātihi (the fair in itself).
When the routes of a ḥasan li-dhātihi narration multiply, the ḥadīth is upgraded to al-ṣaḥīḥ li-ghayrihi (the sound by virtue of something other than itself).
Khabar al-wāḥid is categorised, with respect to acceptance and rejection, into al-ṣaḥīḥ, al-ḥasan, and al-ḍaʿīf.
An omission of two or more consecutive narrators at any point in the chain — this is al-muʿḍal.
