Ḥadīth (/ˈhædɪθ/ or /hɑːˈdiːθ/; Arabic: حديث ḥadīth Arabic pronunciation: [ħadiːθ], pl. Aḥādīth, أحاديث, ʼaḥādīth Arabic pronunciation: [ʔaħadiːθ], also "Traditions") in Islam are the record of the words, actions, and the silent approval, of the Islamic prophet Muhammad. Within Islam the authority of Ḥadīth as a source for religious law and moral guidance ranks second only to that of the Qur'an (which Muslims hold to be the word of Allah revealed to his messenger Muhammad). Quranic verses (such as 24:54, 33:21) enjoin Muslims to emulate Muhammad and obey his judgements, providing scriptural authority for ahadith. While the number of verses pertaining to law in the Quran is relatively few, ahadith give direction on everything from details of religious obligations (such as Ghusl or Wudu, ablutions for salat prayer), to the correct forms of salutations and the importance of benevolence to slaves. Thus the "great bulk" of the rules of Sharia (Islamic law) are derived from ahadith, rather than the Qur'an.
Ḥadīth is the Arabic word for speech, report, account, narrative.:471 Unlike the Qur'an, not all Muslim believe Ahadith accounts (or at least not all ahadith accounts) are divine revelation. Ahadith were not written down by Muhammad's followers immediately after his death but several generations later when they were collected, collated and compiled into a great corpus of Islamic literature. Different collections of Aḥādīth would come to differentiate the different branches of the Islamic faith. A small minority of Muslims called Quranists reject all Ḥadīth.
Because some ahadith include questionable and even contradictory statements, the authentication of ahadith became a major field of study in Islam. In its classic form a hadith has two parts — the chain of narrators who have transmitted the report (the isnad), and the main text of the report (the matn). Individual hadith are classified by Muslim clerics and jurists into categories such as sahih ("authentic"), hasan ("good") or da'if ("weak"). However, different groups and different scholars may classify a hadith differently.
Among some scholars of Sunni Islam the term hadith may include not only the words, advice, practices, etc. of Muhammad, but also those of his companions. In Shia Islam, Ḥadīth is the embodiment of the sunnah, the words and actions of the Prophet and his family the Ahl al-Bayt (The Twelve Imams and the Prophet's daughter, Fatimah).
In Arabic, the noun ḥadīth (حديث IPA: [ħæˈdiːθ]) means "report", "account", or "narrative". Its Arabic plural is aḥādīth (أحاديث [ʔæħæːˈdiːθ]). Hadith also refers to the speech of a person.
In Islamic terminology, according to Juan Campo, the term hadith refers to reports of statements or actions of Muhammad, or of his tacit approval or criticism of something said or done in his presence.
Scholar Patricia Crone includes reports by others than Muhammad in her definition of hadith — "short reports (sometimes just a line or two) recording what an early figure, such as a companion of the prophet (known as sahabah) or Mohammed himself, said or did on a particular occasion, prefixed by a chain of transmitters". But she adds that "nowadays, hadith almost always means hadith from Mohammed himself."
Other associated words possess similar meanings including: khabar (news, information) often refers to reports about Muhammad, but sometimes refers to traditions about his companions and their successors from the following generation; conversely, athar (trace, vestige) usually refers to traditions about the companions and successors, though sometimes connotes traditions about Muhammad.
However, according to the Shia Islam Ahlul Bayt Digital Library Project, "... when there is no clear Qur’anic statement, nor is there a Hadith upon which Muslim schools have agreed. ... Shi’a ... refer to Ahlul-Bayt for deriving the Sunnah of Prophet" — implying that while Hadith in limited to the "Traditions" of Muhammad, the Shia Sunna draws on the sayings, etc. of the Ahlul-Bayt i.e. the Imams of Shia Islam.
The word sunnah (custom or "all the traditions and practices" of the Islamic prophet that "have become models to be followed" by Muslims) is also used in reference to a normative custom of Muhammad or the early Muslim community.
Joseph Schacht describes hadith as providing "the documentation" of the Sunnah.
Another source (Joseph A. Islam) distinguishes between the two saying:
Whereas the 'Hadith' is an oral communication that is allegedly derived from the Prophet or his teachings, the 'Sunna' (quite literally: mode of life, behaviour or example) signifies the prevailing customs of a particular community or people. ... A 'Sunna' is a practice which has been passed on by a community from generation to generation en masse, whereas the Ahadith are reports collected by later compilers often centuries removed from the source. ... A practice which is contained within the Hadith may well be regarded as Sunna, but it is not necessary that a Sunna would have a supporting hadith sanctioning it.
Joseph Schacht quotes a Hadith by Muhammad that is used "to justify reference" in Islamic law to companions of Muhammad as religious authorities — "My companions are like lodestars." According to Schacht, (and other scholars) in the very first generations after the death of Muhammad, use of hadith from Sahabah ("companions" of Muhammad) and Tabi‘un ("successors" of the companions) "was the rule", while use of hadith of Muhammad himself by Muslims was "the exception". Schacht credits Al-Shafi‘i — founder of the Shafi'i school of fiqh (or madh'hab) — with establishing the principle of the use of the ahadith of the Muhammad for Islamic law, and emphasizing the inferiority of hadith of anyone else, saying ahadith
"from other persons are of no account in the face of a tradition from the Prophet, whether they confirm or contradict it; if the other persons had been aware of the tradition from the Prophet, they would have followed it".
This led to "the almost complete neglect" of traditions from Companions and others.
Collections of ahadith sometimes mix those of Muhammad with the reports of others. Muwatta Imam Malik is usually described as "the earliest written collection of hadith" but sayings of Muhammad are “blended with the sayings of the companions”, (822 hadith from Muhammad and 898 from others, according to the count of one edition). In Introduction to Hadith by Abd al-Hadi al-Fadli, Kitab Ali is referred to as "the first hadith book of the Ahl al-Bayt (family of Muhammad) to be written on the authority of the Prophet".
The theological importance of ahadith comes from several verses in the Quran such as:
Say: Obey Allah and obey the Messenger, but if you turn away, he (the Prophet) is only responsible for the duty placed on him (i.e. to convey Allah’s Message) and you for that placed on you. If you obey him, you shall be on the right guidance. The Messenger’s duty is only to convey (the message) in a clear way. (An-Nur 24:54)
In God's messenger you have indeed a good example for everyone who looks forward with hope to God and the Last Day, and remembers God unceasingly. (Al-Ahzab 33: 21)
The hadith literature is based on spoken reports in circulation after the death of Muhammad. Unlike the Qur'an, ahadith were not promptly written down during Muhammad's life or immediately after his death. Hadith were evaluated and gathered into large collections during the 8th and 9th centuries, generations after the death of Muhammad, after the end of the era of the "rightful" Rashidun Caliphate, over 1,000 km (620 mi) from where Muhammad lived. "Many thousands of times" more numerous than Quranic verse, ahadith have been described as resembling layers surrounding the “core” of the Islamic belief (the Quran). Well-known, widely accepted Hadiths make up the narrow inner layer, with ahadith becoming less reliable and accepted with each layer stretching outward.
Unlike the Quran, ahadith are “grounded in the prosaic moments of everyday life". The reports of behavior to be emulated that were collected include details of ritual religious practice such as the five salat (obligatory Islamic prayers) that are not found in the Quran, but also everyday behavior such as table manners, dress, posture. Hadith are also regarded by Muslims as important tools for understanding things mentioned in the Quran but not explained, a source for tafsir (commentaries written on the Quran).
Some important elements, which are today taken to be a long-held part of Islamic practice and belief are not mentioned in the Qur'an at all, but are derived solely from the hadith. Almost all Muslims, therefore, can be called Hadithists (i.e. believers in hadith), and maintain that the ahadith are a necessary requirement for the true and proper practice of Islam, as it gives Muslims the nuanced details of Islamic practice and belief in areas where the Qur'an is silent. Quranists, on the contrary, hold that if the Qur'an is silent on some matter, it is because Allah did not hold its detail to be of consequence; and that some ahadith contradict the Qur'an, evidence that some ahadith are a source of corruption and not a compliment to the Quran.
A classical example is salat (the five daily prayers of Islam), which is commanded in the Qur'an, and considered by all Muslims to be an obligatory part of Islamic religious practice -- one of the five pillars of Islam. Details of prescribed movements and words of the prayer (known as rakat) and how many times they are to be performed, are found in ahadith, demonstrating to Hadithists that ahadith "validly" fulfill the Qur'anic command of ritual prayer. However, ahadith differ on these details and consequently salat is performed differently by different hadithist Islamic sects. (Quranists, for their part, believe if Allah thought the details of salat to be consequence, would have included them in the Quran and that the details of salat are a matter between each individual Muslim and Allah, with correctly performed salat depending on a correct intention to perform the prayers, valid however it may be individually performed.)
Among most hadithists, the importance of ahadith is secondary to Qur'an given that, at least in theory, an Islamic conflict of laws doctrine holds Qur'anic supremacy above ahadith in developing Islamic jurisprudence. However, a minority of hadithists have historically placed ahadith on a par with the Qur'an. A smaller minority have upheld ahadith in contradiction to the Qur'an, thereby placing ahadith above Qur'an and claiming that contradictory ahadith abrogate the parts of the Qur'an where they conflict.
It has been narrated through a chain of narrators, including Muhammad ibn Isma'il and originating with Imam Ja'far al-Sadiq, that the Prophet Muhammad once addressed his people in Mina saying ‘O people, whatever comes to you in the form of my Hadith, if it agrees with the Holy Book of Allah, it is genuine, but whatever comes to you that does not agree with the book of Allah you must know that I have not said it.' :5
The hadith had a profound and controversial influence on tafsir (commentaries of the Quran). The earliest commentary of the Quran known as Tafsir Ibn Abbas is sometimes attributed to the companion Ibn Abbas.
The hadith were used in forming the basis of Sharia (the religious law system forming part of the Islamic tradition), and fiqh (Islamic jurisprudence). The hadith are at the root of why there is no single fiqh system, but rather a collection of parallel systems within Islam.
Much of early Islamic history available today is also based on the hadith, although it has been challenged for its lack of basis in primary source material and the internal contradictions of the secondary material available.
According to as-Sayyid ash-Sharif al-Jurjani, the hadith qudsi differ from the Quran in that the former are "expressed in Muhammad's words", whereas the latter are the "direct words of God". A hadith qudsi need not be a sahih (sound hadith), but may be da‘if or even mawdu‘.
An example of a hadith qudsi is the hadith of Abu Hurairah who said that Muhammad said:
When God decreed the Creation He pledged Himself by writing in His book which is laid down with Him: My mercy prevails over My wrath.
The two major aspects of a hadith are the text of the report (the matn), which contains the actual narrative, and the chain of narrators (the isnad), which documents the route by which the report has been transmitted. The isnad was an effort to document that a hadith had actually come from Muhammad, and Muslim scholars from the eighth century until today have never ceased repeating the mantra "The isnad is part of the religion — if not for the isnad, whoever wanted could say whatever they wanted." The isnad means literally 'support', and it is so named due to the reliance of the hadith specialists upon it in determining the authenticity or weakness of a hadith. The isnad consists of a chronological list of the narrators, each mentioning the one from whom they heard the hadith, until mentioning the originator of the matn along with the matn itself.
The first people to hear hadith were the companions who preserved it and then conveyed it to those after them. Then the generation following them received it, thus conveying it to those after them and so on. So a companion would say, "I heard the Prophet say such and such." The Follower would then say, "I heard a companion say, 'I heard the Prophet.'" The one after him would then say, "I heard someone say, 'I heard a Companion say, 'I heard the Prophet..." and so on.
Different branches of Islam refer to different collections of hadith, though the same incident may be found in hadith in different collections:
In general, the difference between Shi'a and Sunni collections is that Shia give preference to ahadith credited to the Prophet's family and close associates (Ahl al-Bayt), while Sunnis do not consider family lineage in evaluating aHadith and Sunnah narrated by any of twelve thousand companions of Muhammad.
Traditions of the life of Muhammad and the early history of Islam were passed down mostly orally for more than a hundred years after Muhammad's death in AD 632. Muslim historians say that Caliph Uthman ibn Affan (the third khalifa (caliph) of the Rashidun Caliphate, or third successor of Muhammad, who had formerly been Muhammad's secretary), is generally believed to urge Muslims to record the hadith just as Muhammad suggested to some of his followers to write down his words and actions.
Uthman's labours were cut short by his assassination, at the hands of aggrieved soldiers, in 656. No sources survive directly from this period so we are dependent on what later writers tell us about this period.
According to British historian of Arab world Alfred Guillaume, it is "certain" that "several small collections" of hadith were "assembled in Umayyad times."
In Islamic law, the use of hadith as now understood (hadith of Muhammad with documentation, isnads, etc.) came gradually. According to scholars such as Joseph Schacht, Ignaz Goldziher, and Daniel W. Brown, early schools of Islamic jurisprudence used rulings of the Prophet’s Companions, the rulings of the Caliphs, and practices that “had gained general acceptance among the jurists of that school”. On his deathbed, Caliph Umar instructed Muslims to seek guidance from the Qur’an, the early Muslims (muhajirun) who emigrated to Medina with Muhammad, the Medina residents who welcomed and supported the muhajirun (the ansar), the people of the desert, and the protected communities of Jews and Christians (ahl al-dhimma). But did not mention Muhammad
According to scholars Harald Motzki and Daniel W. Brown. The earliest Islamic legal reasonings that have come down to us were "virtually hadith-free", but gradually, over the course of second century A.H. "the infiltration and incorporation of Prophetic ahadith into Islamic jurisprudence" took place.
It was Abū ʿAbdullāh Muhammad ibn Idrīs al-Shāfiʿī (150-204 AH), known as al-Shafi'i who emphasized the final authority of a hadith of Muhammad, so that even the Qur'an was "to be interpreted in the light of traditions (i.e. hadith), and not vice versa." While traditionally the Quran is considered above the Sunna in authority, Al-Shafi'i "forcefully argued" that the sunna stands "on equal footing with the Quran", (according to scholar Daniel Brown) for (as Al-Shafi'i put it) “the command of the Prophet is the command of God.”  
In 851 the rationalist Mu`tazila school of thought fell from favor in the Abbasid Caliphate. The Mu`tazila, for whom the "judge of truth ... was human reason," had clashed with traditionists who looked to the literal meaning of the Quran and hadith for truth. While the Quran had been officially compiled and approved, hadiths had not. One result was the number of hadiths began "multiplying in suspiciously direct correlation to their utility" to the quoter of the hadith (Traditionists quoted hadith warning against listening to human opinion instead of Sharia; Hanafites quoted a hadith stating that "In my community there will rise a man called Abu Hanifa [the Hanafite founder] who will be its guiding light". In fact one agreed upon hadith warned that, "There will be forgers, liars who will bring you hadiths which neither you nor your forefathers have heard, Beware of them." In addition the number of hadith grew enormously. While Malik ibn Anas had attributed just 1720 statements or deeds to the Muhammad, it was no longer unusual to find people who had collected a hundred times that number of hadith.
Faced with a huge corpus of miscellaneous traditions supported differing views on a variety of controversial matters—some of them flatly contradicting each other—Islamic scholars of the Abbasid sought to authenticate hadith. Scholars had to decide which hadith were to be trusted as authentic and which had been invented for political or theological purposes. To do this, they used a number of techniques which Muslims now call the science of hadith.
Sunni and Shia hadith collections differ because scholars from the two traditions differ as to the reliability of the narrators and transmitters. Narrators who took the side of Abu Bakr and Umar rather than Ali, in the disputes over leadership that followed the death of Muhammad, are seen as unreliable by the Shia; narrations sourced to Ali and the family of Muhammad, and to their supporters, are preferred. Sunni scholars put trust in narrators, such as Aisha, whom Shia reject. Differences in hadith collections have contributed to differences in worship practices and shari'a law and have hardened the dividing line between the two traditions.
In the Sunni tradition, the number of such texts is somewhere between seven and thirteen thousand, but the number of ahadith is far greater because several isnad sharing the same text are each counted as individual ahadith. If, say, ten companions record a text reporting a single incident in the life of Muhammad, hadith scholars can count this as ten hadiths. So Musnad Ahmad, for example, has over 30,000 hadiths—but this count includes texts that are repeated in order to record slight variations within the text or within the chains of narrations. Identifying the narrators of the various texts, comparing their narrations of the same texts to identify both the soundest reporting of a text and the reporters who are most sound in their reporting occupied experts of hadith throughout the 2nd century. In the 3rd century of Islam (from 225/840 to about 275/889), hadith experts composed brief works recording a selection of about two- to five-thousand such texts which they felt to have been most soundly documented or most widely referred to in the Muslim scholarly community. The 4th and 5th century saw these six works being commented on quite widely. This auxiliary literature has contributed to making their study the place of departure for any serious study of hadith. In addition, Bukhari and Muslim in particular, claimed that they were collecting only the soundest of sound hadiths. These later scholars tested their claims and agreed to them, so that today, they are considered the most reliable collections of hadith. Toward the end of the 5th century, Ibn al-Qaisarani formally standardized the Sunni canon into six pivotal works, a delineation which remains to this day.
Over the centuries, several different categories of collections came into existence. Some are more general, like the muṣannaf, the muʿjam, and the jāmiʿ, and some more specific, either characterized by the topics treated, like the sunan (restricted to legal-liturgical traditions), or by its composition, like the arbaʿīniyyāt (collections of forty hadiths).
Shi'a Muslims hardly ever use the six major hadith collections followed by the Sunni, as they never usually trust many of the Sunni narrators and transmitters. They have their own extensive hadith literature. The best-known hadith collections are The Four Books, which were compiled by three authors who are known as the 'Three Muhammads'. The Four Books are: Kitab al-Kafi by Muhammad ibn Ya'qub al-Kulayni al-Razi (329 AH), Man la yahduruhu al-Faqih by Muhammad ibn Babuya and Al-Tahdhib and Al-Istibsar both by Shaykh Muhammad Tusi. Shi'a clerics also make use of extensive collections and commentaries by later authors.
Unlike Sunnis, Shia do not consider any of their hadith collections to be sahih (authentic) in their entirety. Therefore, every individual hadith in a specific collection must be investigated separately to determine its authenticity.
Regarding the importance of maintaining accuracy in recording Hadith, it has been reported that Imam Muhammad al-Baqir has said that "Holding back in a doubtful issue is better than entering destruction. Your not narrating a Hadith is better than you narrating a Hadith in which you have not studied thoroughly. On every truth, there is a reality. Above every right thing, there is a light. Whatever agrees with the book of Allah you must take it and whatever disagrees you must leave it alone.":10.
The mainstream sects consider hadith to be essential supplements to, and clarifications of, the Quran, Islam's holy book, as well as for clarifying issues pertaining to Islamic jurisprudence. Ibn al-Salah, a hadith specialist, described the relationship between hadith and other aspect of the religion by saying: "It is the science most pervasive in respect to the other sciences in their various branches, in particular to jurisprudence being the most important of them." "The intended meaning of 'other sciences' here are those pertaining to religion," explains Ibn Hajar al-Asqalani, "Quranic exegesis, hadith, and jurisprudence. The science of hadith became the most pervasive due to the need displayed by each of these three sciences. The need hadith has of its science is apparent. As for Quranic exegesis, then the preferred manner of explaining the speech of God is by means of what has been accepted as a statement of Muhammad. The one looking to this is in need of distinguishing the acceptable from the unacceptable. Regarding jurisprudence, then the jurist is in need of citing as an evidence the acceptable to the exception of the later, something only possible utilizing the science of hadith."
According to Bernard Lewis, "in the early Islamic centuries there could be no better way of promoting a cause, an opinion, or a faction than to cite an appropriate action or utterance of the Prophet." To fight these forgeries, the elaborate science of hadith studies was devised. Hadith studies use a number of methods of evaluation developed by early Muslim scholars in determining the veracity of reports attributed to Muhammad. This is achieved by analyzing the text of the report, the scale of the report's transmission, the routes through which the report was transmitted, and the individual narrators involved in its transmission. On the basis of these criteria, various classifications were devised for hadith. The earliest comprehensive work in hadith studies was Abu Muhammad al-Ramahurmuzi's al-Muhaddith al-Fasil, while another significant work was al-Hakim al-Naysaburi's Ma‘rifat ‘ulum al-hadith. Ibn al-Salah's ʻUlum al-hadith is considered the standard classical reference on hadith studies.
By means of hadith terminology, hadith are categorized as ṣaḥīḥ (sound, authentic), ḍaʿīf (weak), or mawḍūʿ (fabricated). Other classifications used also include: ḥasan (good), which refers to an otherwise ṣaḥīḥ report suffering from minor deficiency, or a weak report strengthened due to numerous other corroborating reports; and munkar (denounced) which is a report that is rejected due to the presence of an unreliable transmitter contradicting another more reliable narrator. Both sahīh and hasan reports are considered acceptable for usage in Islamic legal discourse. Classifications of hadith may also be based upon the scale of transmission. Reports that pass through many reliable transmitters at each point in the isnad up until their collection and transcription are known as mutawātir. These reports are considered the most authoritative as they pass through so many different routes that collusion between all of the transmitters becomes an impossibility. Reports not meeting this standard are known as aahad, and are of several different types.
Another area of focus in the study of hadith is biographical analysis (‘ilm al-rijāl, lit. "science of people"), in which details about the transmitter are scrutinized. This includes analyzing their date and place of birth; familial connections; teachers and students; religiosity; moral behaviour; literary output; their travels; as well as their date of death. Based upon these criteria, the reliability (thiqāt) of the transmitter is assessed. Also determined is whether the individual was actually able to transmit the report, which is deduced from their contemporaneity and geographical proximity with the other transmitters in the chain. Examples of biographical dictionaries include: Abd al-Ghani al-Maqdisi's Al-Kamal fi Asma' al-Rijal, Ibn Hajar al-Asqalani's Tahdhīb al-Tahdhīb and al-Dhahabi's Tadhkirat al-huffaz.
Related article: Goldziher on Hadīth
The major points of intra-Muslim criticism of the Hadith literature is based in questions regarding its authenticity. However, Muslim criticism of ahadith is also based on theological and philosophical Islamic grounds of argument and critique.
With regard to clarity, Imam Ali al-Ridha has narrated that "In our Hadith there are Mutashabih (unclear ones) like those in al-Quran as well as Muhkam (clear ones) like those of al-Quran. You must refer the unclear ones to the clear ones.” :15.
Muslim scholars have a long history of questioning the Hadith literature throughout Islamic history. Western academics also became active in the field later on.