One of the main reasons that hastened the collection of hadiths was the emergence of political sects such as al-Hawāric and al-Ghāliyya immediately after the martyrdom of Hazrat ‘Uthman, and the emergence of theological sects such as al-Qadariyya and al-Murjie from the end of the first (VIIth) century, and al-Jahmiyya and al-Mushabbiah a little later. The fact that the followers of these sects, who were against the conservative majority, denied the hadiths that did not suit them and fabricated hadiths in order to reinforce their views led the people who were busy collecting hadiths to think about the issue and take measures. Especially the invention of narrations in favour of the caliphs by the Shī’a’s own groups and later by the supporters of the Abbasid caliphate, as well as the fabrication and dissemination of hadiths in line with their own ideas by some vested interests, ignorant people who were caught up in racial and sectarian prejudice, and opponents of Islam, and the fact that some people responded to them by fabricating hadiths, albeit with good intentions (bk. MEVZÛ), changed the approach of muhaddithis who did not support the collection of hadiths to this issue. In addition, such developments led them to be more cautious about careless and insincere narrators, to ask from whom the hadiths they narrated were taken, and to avoid the narrations of innovators (al-Dārimī, “Muḳaddimah”, 38), and from the first half of the first (VIIIth) century the issue of isnad in narration came to the fore. Since the introduction of isnad, the narrations of the Ahl al-Sunnah were accepted and the narrations of the Ahl al-Bid’ah were excluded (Muslim, “Muḳaddimah”, 5). As a result, those who regarded hadith as a field of specialisation followed the narrators meticulously and investigated their lives, their piety and honesty, whether they were involved in bid’ah, especially whether they told lies, and whether their memory was weak; thus, the science of jarh wa ta’dīl was born in the first century, and as a result, a large body of knowledge was accumulated about the narrators’ biographies.

A letter of ‘Abd al-‘Azīz b. Marwān, the Umayyad governor of Egypt between 684 and 705, shows that even statesmen were unofficially interested in the editing of hadīths in order to protect them from malicious people. In this letter, ‘Abd al-‘Azīz b. Marwān wrote to the muhaddithī Qāshīr b. Murra al-Hadramī, who is said to have interviewed seventy Companions who participated in the Badr Campaign, and after stating that he had the narrations of Abū Hurayrah, he asked him to write down the hadiths he had heard from other Companions and send them to him. Although the outcome of this letter is not known, when Caliph ‘Umar b. ‘Abd al-‘Aziz realised that the prominent scholars would no longer oppose the writing of hadiths, he decided to officially start the editing process in order to prevent insincere people from damaging the hadiths and to save the authentic hadiths, which had not been gathered together until that day, from being lost. The caliph sent a letter to the governors, the people of Medina, and prominent scholars, as well as to Abū Bakr b. Ḥazm, the governor and qadi of Medina, expressing his concern about the loss of hadīth due to the death of the scholars and his desire that the Prophet’s hadīths and sunnahs be researched and written down (Dārimī, “Muḳaddima,” 43; Bukhārī, “ʿIlim,” 34; Khatīb, Taḳyīd al-ʿilm, p. 106). Ibn Shihāb al-Zuhrī (d. 124/742), who wrote down the fatwas of the companions with the idea that they were sunnah and even had a large number of books in which he recorded every narration he heard, was the first of the muhaddiths to follow his orders by compiling the hadiths he could access and sending them to the caliph. ‘Umar b. ‘Abd al-‘Abd al-‘Aziz also reproduced these hadiths and sent them to various regions (Ibn ‘Abd al-Bar, I, 331). Aside from the sahīfas penned by the Sahāba, it is now known with documents that some 400 hadiths were written down by some 400 muhaddiths in the second half of the first (VIIth) century and the first half of the second (VIIIth) century (M. Mustafa al-A’zamī, Hadith Literature of the First Period, pp. 58-161; Imtiyāz Ahmad, pp. 416-590).

When the hadiths were completed, the efforts to organise them into systematic books and thus to develop methods that would enable the searchers to find the hadiths easily gained weight. While some scholars tried to classify the hadiths according to their subjects and write works in the genre called “musannaf” in this way, others preferred to compose books in the genre called “musnad” by ordering the hadiths according to the names of the Companions who were the first narrators. Although it is not known who first began to order the hadiths according to their fathers, according to the information given by al-Tirmidhī (Kitāb al-ʿIlāl, p. 738) and more extensively by Rāmhurmūzī, Ibn Jurayj (d. 150/767) in Mecca with his works generally called al-Muṣannaf (al-Jāmiʿ, al-Sunnān, al-Muvaṭṭaʾ), Ibn Jarīj (d. 150/767) in Mecca, Ma’mer b. Rāshid in Yemen, Ibn Abū Arūba and Rabi’ b. Sabīh (Subaykh) in Basra, Sufyān al-Sawrī in Kufa, Mālik b. Anas in Medina, ‘Abdullah b. ‘Abdullah in Khorasan. Anas in Medina, ‘Abdullah b. Mubārak in Khorasan, Jarīr b. ‘Abd al-Hamīd in Rey, and Walīd b. Muslim in Damascus (al-Muḥaddis̱ü’l-fāṣil, pp. 611-614). The fact that some of the muhaddiths known for their first classification works died in the middle of the second (VIIIth) century shows that these works were prepared from the first quarter of the same century, and therefore it is not possible to distinguish between the works of al-adwīn and classification with a clear line. The surviving work of the Yemeni muhaddith Maʿmar b. Rāshid, al-Jāmiʿ, gives an idea about the general structure of the first classificatory works (see Literature). In the works classified in the second (VIIIth) century and in most of the hadith books written in the first half of the third (IXth) century, the hadiths of the Prophet were not separated from the opinions of the Companions and the fatwas of the tābiîn. Mālik b. Anas’s al-Muvaṭṭaʾ bears the distinctive characteristic of this type of writing. In the second (VIIIth) century, other muhaddithis who ensured the transmission of hadiths to later generations with their strong memories, reliable narrations, and accurate criticisms include ‘Abd al-Rahman al-Awzāʾī, Shu’be b. Hajjāj, Hammād b. Salama, Lays b. Sa’d, Jarīr b. ‘Abd al-Ḥamīd, Ismā’il b. Uleyya, ‘Abdullah b. Wahb, Wajī’ b. Jarrah, Sufyān b. Uyayna, Yahyā b. Saīd al-Kattān and ‘Abd al-Rahman b. Mahdī.

Generally, in the third (IXth) century, various systems were applied in hadith books according to different needs. The two most common forms of these are the classification of hadiths according to the names of the narrators (ale al-ricāl) and the subjects (ale al-abwāb). The names of Asad b. Mūsā (d. 212/827), Ubaydullah b. Mūsā al-Absī, Yahyā b. ‘Abd al-Hamīd al-Himmānī, Musaddad b. Musarhed, and Nuaym b. Hammād are mentioned as the first musannīs of the musnāns, which gathered all the narrations of each companion regardless of the degree of soundness, based on the names of the first narrators of the hadiths. Although there is not much information about their works, Abū Dāwūd al-Tayālisī’s (d. 204/819) al-Musnad, Abdullah b. Zubayr al-Humaydī’s (d. 219/834) al-Musnad, which should be considered among the first hadīth collections written in Mecca, and Ahmad b. Hanbal’s (d. 241/855) al-Musnad, one of the most voluminous hadīth collections, have survived (see Literature). In mu’jams, which are books classified according to the names of the narrators, the narrations are organised according to the names of the Companions or the names of the teachers of the muhaddith who classified the mu’jam or the cities where the narrators lived. Tabarānī’s three mu’jām are the most well-known examples of this genre. The first examples of hadīth books that were classified according to their subjects and therefore generally referred to as “musannaf” are Maʿmar b. Rāshid’s al-Jāmiʿi and Mālik b. Anas’s al-Muvaṭṭaʾ. Among the first examples of this genre in the third (IXth) century are Abdurrezzāq al-Sanʿānī’s al-Muṣannaf (d. 211/826-27) and Abū Bakr ibn Abū Shaybah’s al-Muṣannaf (see Literature). The most important hadith books classified in the third century are considered to be the Kütüb-i Sitte. Among these, Bukhārī and Muslim’s al-Jāmiʿu’ṣ-ṣaḥīḥ are considered the two most reliable books of Islam after the Qur’ān, since they aim to collect only authentic hadiths. Although some have pointed to Mālik b. Anas’s al-Muvaṭṭaʾ or ‘Abdullah b. ‘Abd al-Rahman al-Dārimī’s al-Sunān (al-Musnad) as the last of these six books, the common opinion is that the sixth book is Ibn Māja’s al-Sunān. The others are Abū Dāwūd’s al-Sunān, al-Tirmidhī’s al-Jāmiʿ al-ṣaḥīḥ, also known as al-Sunān, and al-Nasāʾī’s al-Sunān, also known as al-Mujtabā. Among the other muhaddiths who contributed to the training of many muhaddiths in this century and whose criticisms on hadiths, their narrators and books of hadith were used are Affān b. Muslim, Saīd b. Mansūr, Ibn Saʿd, Yahyā b. Maʿīn, ʿAli b. Medīnī, Ishaq b. Rāḥūya, Abū Ishaq al-Jūzjānī, Abū al-Hasan al-Ijlī, Abū Zur’a al-Rāzī, Baqī b. Mahlī, Abū Hātim al-Rāzī, Abū Zur’a al-Dimashqī, Ibn Abū Āsim and Bezzār.

In the third (IXth) century, studies on the content of hadiths were also carried out, and Abū Ubayd Qāṣim b. Sallām’s Iarīb al-ḥadīs̱, which he produced in forty years, should be mentioned as an example of this new genre. Afterwards, many books were written in this genre.

Although the tradition of travelling for the study of ḥadīth continued in the IVth (X.) century, since the ḥadīths had already been collected in books, oral narration began to slow down, and compilations and specialisations began to be made from the ḥadīth books created in previous centuries instead of compiling original books. For this reason, scholars have considered the beginning of the IVth century as the end of the al-Mutaqaddimīn period and the beginning of the al-Muqahhāhirīn period. The al-Musnad of Abū Ya’lā al-Mawsīlī (d. 307/919), one of the most renowned muhaddithis of this period, is an important source that contains many reports of the Companions. Ibn Jarīr al-Tabarī, in his original work, Tehẕīb al-ās̱ār (ed. Mahmūd Moḥammad Shāqir, Musnad al-ʿUmar b. Ḫaṭṭāb, Musnad al-ʿAlī b. Abī Ṭālib, Musnad al-ʿAbdillāh b. ʿAbbās, I-IV, Cairo 1403/1982; ed. Nāṣir b. Saʿd al-Rashīd, I-IV, Mecca 1404) brought together the hadiths of the Ashār al-mubashshara, the Ahl al-bayt, and the mawālīn, and a part of Ibn ʿAbbās’ hadith; he stated the reports of the hadiths, their reasons, the disagreements of the scholars about these hadiths, and finally his own preference. Ibn Hudhayme also classified his al-Ṣaḥīḥ (ed. M. Mustafa al-A’zamī, I-IV, Beirut 1395/1975), of which no complete copy is available today. Abū ʿAwāna al-Isferāyīnī, al-Musnad al-muḫraj ʿalā Kitābi Muslim b. al-Ḥajjāj (a part of the work was published under the title Musnad Abī ʿAwāna: Hyderābād 1362/1943), and Ismāʿilī initiated a new type of classification, the “müstahraj” with his al-Mustaḫraj. Later on, various müstahrajs were prepared on Ṣaḥīḥ al-Buḫārī and Ṣaḥīḥ al-Muslim. Abū Jaʿfar al-Taḥāwī wrote his Sharḥ al-Maʿāni al-ʿās̱ār, in which he evaluated the hadīths of ethics, Ibn Hibbān wrote his al-Musnūn al-ṣaḥīḥ (al-Taḳāsīm wa’l-anwāʿ) in a completely different order from the previous hadīth books, and Tabarānī, al-Muʿjam al-awsaṭ and al-Muʿjam al-ṣaġīr, which he organised according to the names of his teachers, and al-Muʿjam al-kabīr, which is more voluminous and alphabetical according to the names of the Companions, Dārakutnī produced al-Sunānī, in which he included a large number of different narrations of hadīths, and Ḥākim al-Nīsābūrī produced al-Mustadrek ʿalā al-Ṣaḥīḥayn.

In the IVth century, important books of dirāyah were also written, which served as a source for later works. Ibn Abū Ḥātim’s al-Jarḥ wa’t-taʿdīl, one of the first works on the criticism of both sika and weak hadīth narrators, was based on the views of his father Abū Ḥātim al-Rāzī and his teacher Abū Zur’a al-Rāzī; Râmhürmuzī’s al-Muḥaddis̱ü’l-fāṣıl bayna al-rāwī wa’l-wāʿī, which is considered to be the first comprehensive study of hadīth; Ibn ‘Adī’s al-Kāmil fī ḍuʿafāʾi al-ricāl, in which he cites the opinions of the critics on weak ḥadīth and gives examples of their narrations; Al-Khatābī’s commentaries on Abū Dāwūd’s al-Sunān under the title Meʿālim al-Sunān and then on Bukhārī’s al-Jāmiʿ al-ṣaḥīḥ under the title Aʿlâm al-sunān, which are considered to be the first works in their field; Khalaf al-Wāsatī’s Eṭrāf al-Ṣaḥīḥayn and Abū Masʿūd al-Dimashkī’s Eṭrāf al-Ṣaḥīḥayn, which are among the first examples of ṭrāf books; Ḥākim al-Nīsābūrī’s Maʿrifat al-ʿulūmi al-ḥadīs̱, one of the first and important sources on usūl al-hadīth.

In the Vth (XIth) century and later periods, the basic characteristic of the studies did not change, and the classifications, which consisted of reorganising the well-known hadīth books in different ways, continued. At the beginning of this century, Abū Nuaym al-Isfahānī (d. 430/1038) wrote al-Musnad al-mustaḫraj ʿalā Ṣaḥīḥi Muslim and Maʿrifat al-ṣaḥāba on the life of the Companions, and the Egyptian muhaddith and historian al-Qudāʾī wrote Shihāb al-aḫbār (Baghdad 1327), in which 897 hadiths with short texts are arranged semi-alphabetically in order to facilitate the use of hadiths. Ahmad b. Husayn al-Bayhaqī, who wrote various works on hadīth, gathered many hadīths, sayings of the companions and tābiîn together with their various narrations in his al-Sunan al-qubrā, and collected 20,881 hadīths, sayings of the companions and tābiîn on which Shāfiʿī jurisprudence is based in his Maʿrifat al-sunan wa al-ās̱ār. In al-Istīʿāb fī maʿrifat al-aṣḥāb, the Andalusian muhaddith Ibn ʿAbd al-Bar al-Namarī, who started to write the lives of all the Companions, included 4225 Companions together with their repetitions; and in Jāmiʿu beyān al-ʿilm, he wrote about the Prophet, the companions, the tābīn, and the Prophet’s companions in relation to knowledge and the collection of knowledge. In al-Jāmiʿu beyānī al-ʿilm, he compiled narrations on the advice and experiences of the Prophet, the companions, the tābiʿīn, and later scholars, together with their senedān; in al-Tamhīd limā fī al-Muvaṭṭaʾ mine al-maʿānī wa al-asānīd, in which he also gave a large place to fiqh al-hadīth, he commented on Imam Mālik’s al-Muvaṭṭṭaʾ. Khatīb al-Baghdādī, who wrote in various branches of dirāyat al-hadīth, wrote Taḳyīd al-ʿilm (ed. Yūsuf al-Ish, Damascus 1949) on the writing of hadīths, al-Jāmiʿ li-aḫlâḳ al-rāwī wa ādābi al-sāmiʿ (ed. Muhammad Re’fet Saīd, al-Kuwayt 1401/1981) and al-Kifāya fī ʿilmi al-rwāya, one of the most important sources of usul al-hadīth. Bukhārī and Muslim’s al-Jāmiʿ al-ṣaḥīḥs, especially in the works entitled al-Jamʿ bayna al-Ṣaḥīḥayn, and for ease of reading, they were usually brought together alphabetically or in the order of a mashnān without mentioning the senedān, and Humaydī in his book al-Jamʿ bayna al-ṣaḥīḥayn in the style of a mashnān (for copies see Brockelmann, GAL Suppl, I, 578), the best example of this genre.

From the second half of the XI century onwards, compilations of various sizes were written with the idea of making selections from important books of hadith, or even bringing all the hadiths together. Hasan b. Aḥmad al-Samarqandī’s (d. 491/1098) Baḥr al-asānīd fī ṣıḥāḥi al-masānīd (Aʿlâm al-nubalāʾ, XIX, 206), which is said to be unprecedented in the Islamic world and to contain 100,000 hadīths in 800 juzes, possibly with duplicate narrations, has an important place among the efforts to classify comprehensive hadīth books. However, this work has not survived until today. Ferrā al-Beghawī’s (d. 516/1122) Meṣābīḥ al-sunna, which contains 4931 (or 4719) hadiths, has attracted great attention for centuries. Begavī first sorted the hadiths he selected from reliable hadith sources, especially from the Qutub al-Sitta, by their senedas, and then gathered the hadiths that Bukhārī and Muslim or one of them included in their sahihs under the title of “sıhāḥ”, and the hadiths that Abū Dāwūd, Tirmidhīzī, al-Nasāʾī, and al-Dārimī included in their sunnahs under the title of “ḥasan”. Khatīb al-Tabrīzī collected 1350 hadiths that were included in the sources of Meṣābīḥ but not in Begavī’s work in a third chapter and named his work Mishkāt al-Maṣābīḥ, and this work was also very popular. The Andalusian muhaddith Rezīn b. Muāwiya al-Sarakustī (d. 535/1140), By replacing Ibn Māja’s al-Sunān with Imam Mālik’s al-Muvaṭṭaʾ, al-Tajrīd li’ṣ-ṣıḥāḥ wa’s-ṣuḥāḥ Sunan (al-Jamʿ bayna al-uṣūli al-sitta or al-Tajrīd fi al-jamʿ bayna al-Muvaṭṭṭaʾ wa al-ṣıḥāḥi al-ḫams), Considering this work inadequate, Majd al-Dīn Ibn al-Asīr reorganised it by putting the book titles in alphabetical order and named it Jāmiʿ al-uṣūl li-eḥādīs̱i al-Rasūl. Meanwhile, Abū al-Faraj Ibn al-Jawzī rearranged most of Ahmad b. Ḥanbal’s al-Musnad and al-Jāmiʿ al-ṣaḥīḥ of al-Bukhārī, Muslim, and Tirmidhī in the order of al-Musnad and called his work Cāmiʿ al-masānīd wa’l-elḳāb (Brockelmann, GAL, I, 662; Suppl, I, 917; ʿAbd al-Hamīd al-Allūjī, pp. 89-90) in seven volumes.

In the seventh (thirteenth) century and later, the tradition of narrating hadīth continued at a slower pace than before, and in the meantime Ibn al-Salāh al-Shahrazūrī wrote his Muḳaddima, also known as ʿUlūm al-ḥadīs̱, which constituted the centrepiece of the study of usul al-ḥadīth and was the subject of hundreds of studies. Radiyy al-Dīn al-Sāgānī’s Mashāriḳ al-anwāri al-nabawiyya (nşr. Ashraf b. ‘Abd al-Maqsūd, Beirut 1409/1989, al-Jamʿ bayna al-Ṣaḥīḥayn) was taught as a textbook for many years. Munzirī, known for his works in the field of hadith, compiled his highly popular al-Tarġīb wa’t-terhīb (I-II, India 1300) by scanning many books. Al-Nawawī, one of the most prolific scholars of this century who also wrote important works in the field of usul al-hadīth, compiled al-Minhāj fī sharḥi Ṣaḥīḥi Muslim, Riyāż al-ṣāliḥīn (Makkah 1302), which is still popular today because it contains hadiths of a social and ethical nature, and al-Aẕkār (Cairo 1306), which brings together hadiths on prayer and dhikr. Zeḥabī (d. 748/1348), who is known for his many books, especially those on the famous personalities, wrote Teẕkirat al-ḥuffāẓ, Mīzān al-iʿtidāl on the weak narrators, and Siyar al-aʿlām al-nubalāʾ (I-XXIII, Beirut 1401-1405/1981-1985) on the well-known muhaddithis.

Abū al-Fidā Ibn Kathīr wrote a book based on the Massa al-Sitta, Ahmad b. Ḥanbal’s al-Musnad, Tabarānī’s three muʿjamīs, Bezzār and Abū Yaʿlā al-Mawsīlī’s musnad, but he could not compile some of Abū Hurayrah’s narrations because he lost his eyesight. 463 narrations of Abū Hurayrah (ed. ‘Abd al-Mu’tī Amīn Kal’acī, I-XXXVII, Beirut 1415/1994) is the product of a great effort. With his Jamʿ al-jawāmiʿi, al-Suyūtī furthered the work begun by Ibn Kathīr.

One of the noteworthy works of the eighteenth (fifteenth) century was the classification of the books of “zawāid”. Nūr al-Dīn al-Haythamī’s (d. 807/1405) Majmaʿu al-zawāʾid, the Egyptian muhaddith Ahmad b. Abū Bakr al-Būsīrī’s many works on zawāʾid, Ibn Ḥajar al-ʿAskālānī, known as the only hadīth scholar of his century, and Ahmad b. ʿAḥmad ibn Ḥājar al-ʿAskalānī, known as the only hadīth scholar of his century. Hanbal, and his al-Maṭṭālib al-ʿāliye, in which he gathered the hadīths that were not included in the Kitāb al-Sitta, although they were included in the musnads of eight well-known muhaddiths, including Ahmad ibn Ḥanbal, are examples of this genre. Among Ibn Ḥajar’s hundreds of hadīth-related works, his Fetḥ al-bārī bi-sharḥi Ṣaḥīḥi al-Buḫārī and al-Iṣāba fī tamyīzi al-ṣaḥāba should be especially noted. The works of Muhammad b. ‘Abd al-Rahman al-Sahāwī (d. 902/1497), al-Maḳāṣıd al-ḥasene (Leknev 1303) and Ismāʿil b. Muhammad al-‘Aljūnī (d. 1162/1749), who collected the hadīths common among the people, the wise sayings known as hadīths, and the mawḍū hadīths. 1162/1749)’s Kashf al-ḫafāʾ wa musīl al-ilbās ʿamma al-tehere mine al-eḥādīs̱i ʿalā al-ṣinati al-nās (I-II, Cairo 1351), a large work on the same subject that includes this work. Süyūtī, who was known for his compilations of hadīths in addition to his various works, started to compile all the hadīth narrations, which he estimated to be around 200,000, by scanning seventy-one sources, some of which have not survived to the present day, but could not complete it due to his death, and his al-Jāmiʿu’l-jawāmiʿ and al-Jāmiʿu’ṣ-ṣaġīr, which contains 10,000 hadīths with short texts selected from this work and listed alphabetically, are important hadīth studies of this period. Al-Muttaqī al-Hindī’s Kenz al-ʿummāl fī suneni al-aḳwāl wa al-efʿāl is the most voluminous book containing hadīth texts. In this work, the hadiths in al-Suyūtī’s two works and Ziyādat al-Jāmiʿi al-ṣaġīr are arranged according to books and chapters, and then these books are alphabetised according to their titles.