Ḥasan li-dhātihi: a chain meets the principal conditions of acceptance, with accuracy somewhat below the highest ṣaḥīḥ standard yet sufficiently reliable in itself.
Ṣaḥīḥ li-ghayrihi: a ḥasan li-dhātihi report may rise through additional credible corroboration to a stronger overall grade.
Ḥasan li-ghayrihi: a report with a remediable weakness in an individual route becomes acceptable through independent, credible supporting evidence.
These grades differ in the source of their evidentiary strength. “Li-dhātihi” refers to adequacy in the route itself; “li-ghayrihi” points to external corroboration, while ṣaḥīḥ li-ghayrihi indicates a stronger resulting grade than ḥasan li-ghayrihi.