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

Among the early traditionists (muhaddithun, scholars of Ahadith), the rules and criteria governing their study of Hadith were meticulous, but some of their terminologies varied from person to person, and their principles began to be systematically written down, but scattered among various books; for example, in Ar-Risalah of Ash-Shafi`i (d. AH 204), the introduction to the Sahih of Muslim (d. AH 261) and the Jami of At-Tirmidhi (d. AH 279). Many of the criteria of early traditionists, for example, Al-Bukhari, were deduced by later scholars from a careful study of which reporters or isnads were accepted and rejected by them.

One of the earliest writings to attempt to cover methodology comprehensively, using standard (generally accepted) terminology, was the work by Ar-Ramahurmuzi (d. AH 360). The next major contribution was Ma`rifat Ulum Al-Hadith by Al-Hakim (d. AH 405), which covered 50 classifications of Hadith, but still left some points untouched; Abu Nu`aim Al-Asbahani (d. AH 430) completed some of the missing parts to this work. After that came Al-Kifayah fi `Ilm ar-Riwayah of Al-Khatib Al-Baghdadi (d. AH 463) and another work on the manner of teaching and studying Ahadith. Later scholars were considered to be greatly indebted to Al-Khatib’s work.

After further contributions by Qadi Iyad Al-Yahsubi (d. AH 544) and Abu Hafs Al-Mayanji (d. AH 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 As-Salah (d. AH 643), commonly known as Muqaddimat Ibn As-Salah (Muqaddimah of Ibn As-Salah), compiled while he taught in the Dar Al-Hadith (Hadith school) of several cities in Syria. Some of the numerous later works based on that of Ibn As-Salah are these:

Al-Irshad, an abridgment of Muqaddimah, by An-Nawawi (d. AH 676), which he later summarized in his Taqrib. As-Suyuti (d. AH 911) compiled a valuable commentary on the latter entitled Tadrib Al-Rawi.

Ikhtisar `Ulum al-Hadith by Ibn Kathir (d. AH 774); Al-Khulasah by Al-Taibi (d. AH 743); Al-Minhal by Badr Ad-Din ibn Jama`ah (d. AH 733); Al-Muqni` by Ibn Al-Mulaqqin (d. AH 802); and Mahasin al-Istilah by Al-Balqini (d. AH 805 ), all of which are abridgments of Muqaddimat Ibn As-Salah.

Nukat by Az-Zarkashi (d. AH 794); At-Taqyid wal-Idah by Al-`Iraqi (d. AH 806); and An-Nukat by Ibn Hajar Al-`Asqalani (d. AH 852), all of which are further notes on the points made by Ibn As-Salah.

Alfiyyat al-Hadith by 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 by As-Sakhawi (d. AH 903); Qatar Ad-Durar by As-Suyuti; and Fath Al-Baqi by Sheikh Zakariya Al-Ansari (d. AH 928).

Other notable treatises on Hadith methodology include the following:

Al-Iqtirah by Ibn Daqiq Al-`Id (d. AH 702); Tanqih al-Anzar by Muhammad ibn Ibrahim Al-Wazir (d. AH 840), which was the subject of a commentary by Al-Amir As-San`ani (d. AH 1182).

Nukhbat Al-Fikr by 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. AH 1014), `Abdur-Ra’uf Al-Munawi (d. AH 1031) and Muhammad ibn Abdul-Hadi As-Sindi (d. AH 1138). Among those who rephrased the Nukhbah in the poetic form are At-Tufi (d. AH 893) and Al-Amir As-San`ani.

Alfiyyat Al-Hadith by As-Suyuti, the most comprehensive poetic work in the field; Al-Manzumah by Al-Baiquni, which was expanded upon by, among others, Az-Zurqani (d. AH 1122) and Nawab Siddiq Hasan Khan (d. AH 1307); Qawaid At-Tahdith by Jamal Ad-Din Al-Qasimi (d. AH 1332).

Tawjih an-Nazar by Tahir Al-Jaza‚iri (d. AH 1338), a summary of Al-Hakim’s Ma`rifah.