Hadith

A "good" hadith, acceptable but ranking below sahih because one of its narrators has slightly less precision; still valid as evidence in Islamic law.

The chain of transmitters who relayed a hadith, each citing the one before. Verifying the isnad is the foundation of authenticating prophetic reports.

A report transmitted by so many narrators at every stage that their collusion on a lie is inconceivable, yielding certain knowledge.

A hadith of the highest grade of authenticity: an unbroken chain of upright, precise narrators reaching the Prophet, free of hidden defects and irregularity.

The recorded words, actions, and tacit approvals of the Prophet Muhammad — the second source of Islamic law after the Quran, preserved through hadith.

A report not reaching the level of mutawatir, transmitted by a limited number of narrators. It yields probable (not certain) knowledge but can still be authentic.

A "weak" hadith that fails one or more conditions of acceptance — through a broken chain or a criticised narrator — and is generally not used to establish rulings.

A "sacred hadith" in which the Prophet reports words from Allah, but whose wording is the Prophet's — distinct from the Quran, which is divine in both meaning and wording.

The science of "criticism and accreditation" — evaluating hadith narrators to declare them reliable or impugn their trustworthiness.

The "Six Books" — the six most authoritative Sunni hadith collections: Bukhari, Muslim, Abu Dawud, al-Tirmidhi, al-Nasa'i, and Ibn Majah.

A report attributed specifically to the Prophet — his words, actions, or tacit approvals — whether the chain is continuous or not.

The actual text or content of a hadith — the words of the Prophet — as distinct from its isnad (chain of narrators).

A fabricated report falsely attributed to the Prophet. It is the worst category and may not be narrated except to expose it as a forgery.

The science of hadith terminology: the rules and definitions by which narrations are classified, graded, and authenticated.

A narrator who transmits a hadith. Each rawi in a chain is scrutinised for uprightness (adala) and accuracy of memory (dabt).

The hadith collection of Imam al-Bukhari (d. 870 CE), regarded by Sunni Muslims as the most authentic book after the Quran.

The hadith collection of Imam Muslim ibn al-Hajjaj (d. 875 CE), ranked second only to Sahih al-Bukhari in authenticity among Sunni Muslims.

A narration attributed to a Companion or Successor (rather than the Prophet). Used broadly, it can refer to any transmitted report.

A report whose chain stops at a Successor (Tabi'i) — the saying or action of one who followed the Companions, not the Prophet himself.

A report whose chain stops at a Companion — recording the Companion's own statement or action rather than the Prophet's.

A scholar of hadith who has mastered the chains, texts, narrators, and sciences of prophetic tradition.

A "denounced" hadith reported by a weak narrator in a way that contradicts more reliable narrators. It is a category of rejected reports.

A hadith in which a Successor (Tabi'i) reports directly from the Prophet, omitting the Companion in between. The gap usually weakens it.

A hadith with a continuous chain reaching the Prophet; also the name of hadith collections arranged by Companion, such as Musnad Ahmad.

An "anomalous" hadith in which a reliable narrator contradicts narrators who are more reliable or more numerous. Its irregularity prevents authentication.

A report or piece of news. In hadith science it is often a synonym for hadith, though some scholars use it for narrations from Companions and others.

An "inverted" hadith in which something — a narrator's name or part of the text — has been swapped or reversed, whether by error or intent.

A "suspended" hadith in which one or more narrators are omitted from the beginning of the chain.

An "interpolated" hadith into which words not part of the original — often a narrator's explanation — have been inserted into the text.

A "broken" hadith with a missing link somewhere in its chain (other than at the Companion level), rendering it weak.