«حَسَنٌ صَحِيحٌ»
The same report is described with both hasan and sahih expressions.
Al-Tirmidhi sometimes uses hasan sahih for a single reported hadith. This raises a problem: hasan ordinarily indicates somewhat lighter precision, while sahih requires the stronger standard. How can both labels appear together?
The response examines the number of routes and differences among critics' judgments. One route may be hasan and another sahih; alternatively, where only one route is known, experts may differ about the narrator's precision. The combined expression need not ascribe two mutually exclusive grades to one isolated isnad in precisely the same respect.