Chapter Eight
Invoking Sound (ṣaḥīḥ), Fair (ḥasan), and Weak (ḍaʿīf) Hadith as Legal Proof

Invoking Sound and Fair Hadith
Citing a sound (ṣaḥīḥ) report as evidence in matters of legal rulings is unanimously agreed upon. The same holds—according to the vast majority of scholars—for a report that is fair in and of itself (ḥasan li-dhātihi); within the sphere of legal argumentation (iḥtijāj) it is grouped with the sound report, even though it stands one rank below it. Likewise, a weak (ḍaʿīf) report that, through multiple transmission routes, rises to the level of “fair due to corroboration” (ḥasan li-ghayrihi) is also accepted by consensus.

Invoking Weak Hadith
The well-known maxim that a weak (ḍaʿīf) hadith may be acted upon in matters of virtuous deeds (faḍāʾil al-aʿmāl) but not elsewhere refers only to each individual chain taken in isolation, not to the collective total. When the various routes are considered together, the hadith moves into the category of fair (ḥasan), not weak—a point expressly stated by the leading authorities.