If a ḥasan li-dhātihi report comes through multiple routes, it becomes al-ṣaḥīḥ li-ghayrihi (the sound by virtue of something other than itself).1
An example: the ḥadīth of Muḥammad ibn ʿAmr ibn ʿAlqama, from Abū Salama, from Abū Hurayra, that the Messenger of Allāh ﷺ said: "Were it not that I would burden my community, I would have ordered them to use the siwāk before every prayer." Muḥammad ibn ʿAmr is light in ḍabṭ, so his ḥadīth is ḥasan; but this ḥadīth has been narrated through other routes as well, and thus became ṣaḥīḥ li-ghayrihi. Drawn from Muqaddimat Ibn al-Ṣalāḥ, p. 35. ↩
If a ḥadīth of slight weakness comes through multiple routes, it becomes al-ḥasan li-ghayrihi (the fair 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.
If the retention (ḍabṭ) is light while the other attributes of ṣaḥīḥ remain present, it is al-ḥasan li-dhātihi (the fair in itself).
A visual summary of the five-grade classification of aḥādīth: ṣaḥīḥ li-dhātihi, ḥasan li-dhātihi, ṣaḥīḥ li-ghayrihi, ḥasan li-ghayrihi and ḍaʿīf.
