Com o passar do tempo, mais transmissores passaram a integrar cada isnad, e por isso a situação exigia uma disciplina rigorosa na aceitação dos ahadith; as regras que regulam essa disciplina são conhecidas como Mustalah al-Hadith (a Classificação do Hadith).

As time passed, more reporters were involved in each isnad, and so the situation demanded strict discipline in the acceptance of ahadith; the rules regulating this discipline are known as Mustalah al-Hadith (the Classification of Hadith).

Entre os primeiros estudiosos do Hadith (muhaddithin, especialistas em Hadith), as regras e os critérios que regiam o seu estudo eram meticulosos, mas a terminologia de alguns deles variava de pessoa para pessoa, e os seus princípios começaram a ser registados por escrito de forma sistemática, porém dispersos por vários livros, como, por exemplo, na Al-Risalah de al-Shafi'i (m. 204), na Introdução ao Sahih de Muslim (m. 261) e no Jami' de al-Tirmidhi (m. 279). Muitos dos critérios dos primeiros estudiosos do Hadith, como al-Bukhari, foram deduzidos por estudiosos posteriores a partir de um estudo cuidadoso de quais transmissores ou isnads eram aceites e rejeitados por eles.

Amongst the early traditionists (muhaddithin, scholars of Hadith), the rules and criteria governing their study of Hadith were meticulous but some of their terminology varied from person to person, and their principles began to be systematically written down, but scattered amongst various books, e.g. in Al-Risalah of al- Shafi'i (d. 204), the Introduction to the Sahih of Muslim (d. 261) and the Jami' of al-Tirmidhi (d. 279); many of the criteria of early traditionists, e.g. al-Bukhari, were deduced by later scholars from a careful study of which reporters or isnads were accepted and rejected by them.

Uma das primeiras obras a tentar abranger o Mustalah de forma completa, usando a terminologia geralmente aceite, foi a de al-Ramahurmuzi (m. 360). A contribuição seguinte de grande relevo foi Ma'rifah 'Ulum al-Hadith, de al-Hakim (m. 405), que abordava cinquenta classificações do Hadith, mas deixava alguns pontos por tratar; Abu Nu'aim al-Isbahani (m. 430) completou algumas das partes em falta desta obra. Depois surgiram Al-Kifayah fi 'Ilm al-Riwayah, de al-Khatib al-Baghdadi (m. 463), e outra obra sobre a forma de ensinar e estudar o Hadith; considerou-se que os estudiosos posteriores ficaram muito em dívida para com o trabalho de al-Khatib.

One of the earliest writings to attempt to cover Mustalah comprehensively, using standard (i.e. generally-accepted) terminology, was the work by al-Ramahurmuzi (d. 360). The next major contribution was Ma'rifah 'Ulum al-Hadith by al- Hakim (d. 405), which covered fifty classifications of Hadith, but still left some points untouched; Abu Nu'aim al-Isbahani (d. 430) completed some of the missing parts to this work. After that came Al-Kifayah fi 'Ilm al- Riwayah of al-Khatib al-Baghdadi (d. 463) and another work on the manner of teaching and studying Hadith; later scholars were considered to be greatly indebted to al-Khatib's work.

Após as contribuições posteriores de Qadi 'Iyad al-Yahsubi (m. 544) e Abu Hafs al-Mayanji (m. 580), entre outros, surgiu a obra que, embora modesta em tamanho, foi tão abrangente em seu excelente tratamento do assunto que se tornou a referência padrão para milhares de estudiosos e estudantes de Hadith ao longo de muitos séculos, até os dias atuais: o 'Ulum al-Hadith de Abu 'Amr 'Uthman Ibn al-Salah (m. 643), comumente conhecido como Muqaddimah Ibn al-Salah, compilado enquanto ele lecionava na Dar al-Hadith de várias cidades da Síria. Algumas das numerosas obras posteriores baseadas na de Ibn al-Salah são:

After further contributions by Qadi 'Iyad al- Yahsubi (d. 544) and Abu Hafs al-Mayanji (d. 580) among others, came the work which, although modest in size, was so comprehensive in its excellent treatment of the subject that it came to be the standard reference for thousands of scholars and students of Hadith to come, over many centuries until the present day: 'Ulum al- Hadith of Abu 'Amr 'Uthman Ibn al-Salah (d. 643), commonly known as Muqaddimah Ibn al-Salah, compiled while he taught in the Dar al-Hadith of several cities in Syria. Some of the numerous later works based on that of Ibn al-Salah are:

• Um resumo da Muqaddimah, Al-Irshad de al-Nawawi (m. 676), que ele posteriormente resumiu em seu Taqrib; al-Suyuti (m. 911) compilou um valioso comentário sobre este último, intitulado Tadrib al-Rawi.

• An abridgement of Muqaddimah, Al-Irshad by al- Nawawi (d. 676), which he later summarised in his Taqrib; al-Suyuti (d. 911) compiled a valuable commentary on the latter entitled Tadrib al-Rawi.

Ikhtisar 'Ulum al-Hadith de Ibn Kathir (m. 774), Al-Khulasah de al-Tibi (m. 743), Al-Minhal de Badr al-Din b. Jama'ah (m. 733), Al-Muqni' de Ibn al-Mulaqqin (m. 802) e Mahasin al-Istilah de al-Balqini (m. 805), todos eles resumos da Muqaddimah de Ibn al-Salah.

• Ikhtisar 'Ulum al-Hadith of Ibn Kathir (d. 774), Al-Khulasah of al-Tibi (d. 743), Al- Minhal of Badr al-Din b. Jama'ah (d. 733), Al- Muqni' of Ibn al-Mulaqqin (d. 802) and Mahasin al-Istilah of al-Balqini (d. 805), all of which are abridgements of Muqaddimah Ibn al- Salah.

• Al-Nukat de al-Zarkashi (m. 794), Al-Taqyid wa 'l-Idah de al-'Iraqi (m. 806) e Al-Nukat de Ibn Hajar al-'Asqalani (m. 852), todos eles notas adicionais sobre os pontos levantados por Ibn al-Salah.

• Al-Nukat of al-Zarkashi (d. 794), Al-Taqyid wa 'l-Idah of al-'Iraqi (d. 806) and Al-Nukat of Ibn Hajar al-'Asqalani (d. 852), all of which are further notes on the points made by Ibn al- Salah.

• *Alfiyyah al-Hadith* de al-'Iraqi, uma reescrita do *Muqaddimah* na forma de um longo poema, que se tornou objeto de vários comentários, incluindo dois (um longo e outro curto) do próprio autor, *Fath al-Mughith* de al-Sakhawi (m. 903), *Qatar al-Durar* de al-Suyuti e *Fath al-Baqi* do Shaykh Zakariyyah al-Ansari (m. 928).

• Alfiyyah al-Hadith of al-'Iraqi, a rewriting of Muqaddimah in the form of a lengthy poem, which became the subject of several commentaries, including two (one long, one short) by the author himself, Fath al-Mughith of al-Sakhawi (d. 903), Qatar al-Durar of al- Suyuti and Fath al-Baqi of Shaykh Zakariyyah al-Ansari (d. 928).

• Al-Iqtirah de Ibn Daqiq al-'Id (m. 702). Tanqih al-Anzar de Muhammad b. Ibrahim al-Wazir (m. 840), objeto de um comentário de al-Amir al-San'ani (m. 1182).

• Al-Iqtirah of Ibn Daqiq al-'Id (d. 702). Tanqih al-Anzar of Muhammad b. Ibrahim al- Wazir (d. 840), the subject of a commentary by al-Amir al-San'ani (d. 1182).

• Nukhbah al-Fikr de Ibn Hajar al-'Asqalani, novamente objeto de diversos comentários, incluindo um do próprio autor, outro de seu filho Muhammad, e os de 'Ali al-Qari (m. 1014), 'Abd al-Ra'uf al-Munawi (m. 1031) e Muhammad b. 'Abd al-Hadi al-Sindi (m. 1138). Entre aqueles que reformularam a Nukhbah em forma poética estão al-Tufi (m. 893) e al-Amir al-San'ani.

• Nukhbah al-Fikr of Ibn Hajar al-'Asqalani, again the subject of several commentaries, including one by the author himself, one by his son Muhammad, and those of 'Ali al-Qari (d. 1014), 'Abd al-Ra'uf al-Munawi (d. 1031) and Muhammad b. 'Abd al-Hadi al-Sindi (d. 1138). Among those who rephrased the Nukhbah in poetic form are al-Tufi (d. 893) and al- Amir al-San'ani.

• Alfiyyah al-Hadith de al-Suyuti, a obra poética mais abrangente do campo. Al-Manzumah de al-Baiquni, que foi ampliada por, entre outros, al-Zurqani (m. 1122) e Nawab Siddiq Hasan Khan (m. 1307). Qawa'id al-Tahdith de Jamal al-Din al-Qasimi (m. 1332).

• Alfiyyah al-Hadith of al-Suyuti, the most comprehensive poetic work in the field. Al-Manzumah of al-Baiquni, which was expanded upon by, amongst others, al-Zurqani (d. 1122) and Nawab Siddiq Hasan Khan (d. 1307). Qawa'id al-Tahdith of Jamal al-Din al-Qasimi (d. 1332).

• Taujih al-Nazar de Tahir al-Jaza'iri (m. 1338), um resumo do Ma'rifah de al-Hakim.

• Taujih al-Nazar of Tahir al-Jaza'iri (d. 1338), a summary of al-Hakim's Ma'rifah.