Outline the three categories of Hadith according to their degrees of reliability.

Three categories of Hadith according to their degrees of reliability

On the basis of the strength of their chain of narrators (isnad) and content (matn), Hadith are graded into three main categories:

1. Sahih (Sound/Authentic): This is Hadith with an unbroken chain of upright narrators possessing accurate memory, free from any hidden defect ('illah) and irregularity (shudhudh). It is fully reliable and binding as a source of law. Example: the Hadith collections of Al-Bukhari and Muslim are dominated by such reports.
2. Hasan (Good): This resembles the Sahih in having a continuous chain of trustworthy narrators, but one or more narrators are slightly weaker in the precision of their memory. It is still acceptable as evidence, though a rank below Sahih.
3. Da'if (Weak): This is Hadith that fails to meet one or more of the conditions of soundness, for example a break in the chain, an unknown narrator, or a narrator accused of poor memory or dishonesty. It is generally not used to establish law, though scholars may cite it in matters of moral encouragement with caution.

Below Da'if, the fabricated report (Mawdu') is completely rejected and must not be attributed to the Prophet.