«وَهَذَا أَوَّلُ تَقْسِيمِ الْمَقْبُولِ إِلَى أَرْبَعَةِ أَنْوَاعٍ»
This begins the fourfold division of accepted reports.
Two questions organize the grades of accepted transmission: does the report itself meet the highest or a slightly lower level of the intrinsic conditions? And do independent routes or credible corroboration raise its grade?
Sahih li-dhatihi: all the strongest intrinsic conditions, including complete precision.
Sahih li-ghayrihi: a hasan-grade report raised to sahih through suitable independent support.
Hasan li-dhatihi: acceptable intrinsic conditions, but less than complete precision.
Hasan li-ghayrihi: a remediable lower-grade report gains adequate corroboration for acceptance.
These categories are related, but merely finding multiple copies of a weak report never guarantees a higher grade without substantive evaluation.