Hadith

Hadith refers to the corpus of reports that record the words, actions and tacit approvals attributed to the Prophet Muhammad in Sunni Islam and to the Prophet and the Ahl al-Bayt in Shia Islam. These reports form a central component of the Islamic tradition and serve, alongside the Qur’an, as a foundational source of religious guidance, legal rulings and ethical norms. Each hadith consists of two parts: the isnad, the chain of transmitters through whom the report was passed down, and the matn, the main text containing the substance of the narration. The study of hadith, which developed into a sophisticated scholarly discipline, has shaped Islamic thought and practice from the second century of the Islamic calendar onwards.

Etymology and Definition

The Arabic term hadith literally denotes a report, account or narrative and may also refer to a person’s speech. In religious terminology, it signifies what is attributed to Muhammad—statements, actions or tacit approval of behaviour witnessed in his presence. The classical scholar Ibn Hajar al-‘Asqalani defined the religious usage as any tradition ascribed to the Prophet that does not appear in the Qur’an. In Shia thought, where the sayings of the Prophet’s family (the Imams) hold authoritative status, the normative corpus of guidance extends beyond prophetic utterance to include the traditions of the Ahl al-Bayt.
Hadith is distinct from but closely linked to sunnah, the normative example considered binding for Muslims. While sunnah originally referred to customary practice without a moral dimension, over time it came to denote the exemplary behaviour of Muhammad. The hadith literature became the principal vehicle through which this sunnah was preserved and transmitted.

Formation of the Hadith Tradition

In the first centuries after Muhammad’s death, scholars known as muhaddithun undertook the systematic collection and examination of hadith. Collections produced in the eighth to tenth centuries CE became the core texts relied upon by Sunni and Shia communities. The process involved compiling reports from a wide range of transmitters, assessing the reliability of each narrator and scrutinising the textual content for coherence and consistency.
Central to this endeavour was the evaluation of the isnad, through which scholars sought to trace a report back to an individual—ideally the Prophet, but in early usage also to companions or successors. The development of hadith collections was gradual. In the earliest period, reports from companions and successors were frequently used for legal and ethical guidance, and only later did the hadith attributed directly to Muhammad assume pre-eminence. The jurist al-Shafi‘i played a crucial role in establishing prophetic hadith as the paramount authority in Islamic law, relegating reports from other early authorities to secondary status.

Categories and Evaluation

Hadith scholars classified narrations according to their perceived reliability. Broad categories include:

• Sahih (authentic): reports whose chains of transmission are sound and whose transmitters are deemed trustworthy.
• Hasan (good): reliable but with minor weaknesses.
• Da‘if (weak): narrations with problematic chains or questionable content.

These evaluations were inherently interpretive, and differing scholarly criteria led to variations in the classification of the same report across schools of law and regions. Canonical Sunni collections such as those of al-Bukhari and Muslim are held in high regard, yet even these have been subject to later scholarly criticism. Shia collections, particularly those emphasising the authority of the Imams, developed their own standards and compendia.
A subset of narrations known as hadith qudsi is regarded by many Muslims as expressing divine meaning in Muhammad’s own words, differing from the Qur’an, which Muslims believe to be the direct word of God expressed verbatim. Hadith qudsi may fall into any category of reliability and are not treated as scripture.

Non-Prophetic Reports

Early collections often mixed prophetic hadith with reports from companions and successors. The Muwatta’ of Imam Malik, regarded as one of the earliest written compendia, contains numerous sayings attributed to companions. Later Sunni tradition tended to restrict the term hadith primarily to reports from Muhammad himself, though non-prophetic narrations continued to inform legal and ethical discourse.

Relationship with Sunnah and Islamic Law

Hadith forms the primary textual basis for the sunnah. The vast majority of Islamic legal rulings in many classical schools derive from narrations rather than direct Qur’anic verses. Reports were used to explain, supplement or qualify Qur’anic teachings, and their integration created a rich corpus of jurisprudence. Differences in the use and grading of hadith contributed to the diversity of legal opinions across madhhabs.
Shia Islam, while accepting hadith attributed to the Prophet, places particular emphasis on narrations transmitted through the Imams, maintaining a broader conception of authoritative sunnah. In both Sunni and Shia contexts, the doctrinal, ethical and ritual dimensions of Islam are deeply shaped by hadith literature.

Criticism and Skepticism

Throughout Islamic history, some groups questioned or rejected the authority of hadith. Early Kharijites and later Mu‘tazilites challenged the use of hadith as a basis for law, although the latter continued to value the sunnah. In modern times, Quranist movements have argued that religious authority should rest solely upon the Qur’an, viewing much of the hadith corpus as later fabrication.
Western academic studies of hadith tend to be sceptical of their historical reliability. Scholars point to the late compilation dates, the difficulty of verifying chains of transmission, the prevalence of fabricated narrations, and the possibility that many hadith reflect theological or political debates from the second and third Islamic centuries rather than the time of Muhammad. Even narrations considered sahih in classical sources are treated cautiously in contemporary historiography.

Evolution of the Concept

Over time, the term hadith expanded from its original, simple sense of narrative to a technical designation for a genre of religious literature grounded in chain-based transmission. This evolution reflected changing understandings of authority, the need for uniform legal principles and the consolidation of Sunni and Shia intellectual traditions.
Today, the study of hadith remains a core discipline in Islamic scholarship, encompassing methods of textual analysis, biographical evaluation and legal interpretation. It also forms a significant area of academic research, contributing to broader discussions about the development of Islamic law, the historical Muhammad and the transmission of early religious memory.