Rules of Islam in the Hanafi Madhhab were transmitted through a chain beginning with 'Abdullah ibn Masud (radi-Allahu 'anh), who was a Sahabi. Al-Imam al-azam Abu Hanifa (rahmat-Allahi ta'ala 'alaih), the founder of the Madhhab, acquired the knowledge of fiqh from Hammad, and Hammad from Ibrahim an-Nakhai. Ibrahim an-Nakhai was taught by Alqama, and Alqama studied under Abdullah ibn Masud, who was educated by Rasulullah (sall-Allahu 'alaihi wa sallam). Abu Yusuf, Imam Muhammad ash-Shaibani, Zufar ibn Hudhail and Hasan ibn Ziyad were al-Imam al-azam's disciples (rahimahum-Allah). Of these, Imam Muhammad wrote about one thousand books on Islamic teachings. He was born in 135 A.H. and passed away in Rayy, Iran, in 189 (805 A.D.). Because he was married to the mother of al-Imam ash-Shafi'i, one of his disciples, all his books were left to Shafi'i upon his death, thus Shafi'i's knowledge increased. For this reason, al-Imam ash-Shafi'i (rahmat-Allahi ta'ala 'alaih) said, 'I swear that my knowledge of fiqh increased by reading Imam Muhammad's books. Those who want to deepen their knowledge of fiqh should be in the company of the disciples of Abu Hanifa.' And once he said, 'All Muslims are like the household, children, of al-Imam al-azam.' That is, as a man earns a living for his wife and children, al-Imam al-azam took it upon himself to find out the religious knowledge which people needed in their affairs. Thus, he spared Muslims of a lot of hard work. Al-Imam al-azam Abu Hanifa (rahmat-Allahi 'alaih) compiled the knowledge of fiqh, classified it into branches and sub-branches, and set usuls (methods) for it. He also collected the knowledge of itiqad as Rasulullah (sall-Allahu 'alaihi wa sallam) and the as-Sahabat al-kiram (ridwan-Allahi 'alaihim ajmain) had preached, and taught them to hundreds of his disciples. Some of his disciples became specialists in 'ilm al-kalam, that is, in the teachings of iman. Of them, Abu Bakr al-Jurjani, one of Imam Muhammad ash-Shaibani's disciples, became famous. And Abu Nasr al-'Iyad, one of his pupils, educated Abu Mansur al-Maturidi in 'ilm al-kalam. Abu Mansur wrote in his books the knowledge of kalam as it came from al-Imam al-azam (rahmat-Allahi ta'ala 'alaih). By contending against heretics, he consolidated the itiqad of the Ahl as-Sunnat. He disseminated it out far and wide. He passed away in Samarqand in 333 (944 A.D.). This great alim and another alim, Abu 'l-Hasan al-Ashari, are called the imams of the Madhhabs of itiqad of the Ahl as-Sunnat. The fiqh scholars are grouped in seven grades. Kamal Pasha Zhada Ahmad ibn Sulaiman Effendi (rahmat-Allahi ta'ala 'alaih), in his work Waqf an-niyyat, explained these seven grades as follows: 1. The mujtahids of Islam, who constructed the methods and principles of deriving tenets from the four sources of the religion (Adilla-i arba'a), and derived tenets in accordance with the principles they established. The four aimmat al-madhahib were of these. 2. The mujtahids in a Madhhab, who, following the principles formulated by the imam of the Madhhab, derived rules from the four sources. They were Imam Abu Yusuf, Imam Muhammad, etc. (rahmat-Allahi ta'ala 'alaihim ajmain). 3. The mujtahids of matters (masala), who for the matters that were not dealt with by the founder of the Madhhab, derived rules using the methods and principles of the Madhhab. Yet in doing this, they had to follow the imam. They were at-Tahawi (238-321 A.H., in Egypt), Hassaf Ahmad ibn 'Umar (d. 261, in Baghdad), 'Abdullah ibn Husain al-Karkhi (340), Shams al-aimma al-Halwani (456, in Bukhara), Shams al-aimma as-Sarahsi (483), Fakhr-ul Islam 'Ali ibn Muhammad al-Pazdawi (400-482, in Samarqand), Qadi-Khan Hasan ibn Mansur al-Farghani (592), etc. (rahmat-Allahi ta'ala 'alaihim ajmain). 4. Ashab at-takhrij, who were not able to employ ijtihad. They were scholars who explained in brief, unclear rules derived by mujtahids. Husam ad-din ar-Razi 'Ali ibn Ahmad (d. 593 A.H., in Damascus) was one of them. He (rahmat-Allahi ta'ala 'alaih) wrote a commentary to Al-Quduri. 5. Arbab at-Tarjih, who preferred one of the several riwayas (narrations or opinions of the mujtahids as narrated) coming from mujtahids. They were Abu l'Hasan al-Quduri (362-428 A.H., in Baghdad) and Burhan ad-din 'Ali al-Marghinani the author of Al-hidaya, who was martyred by the soldiers of Genghis in the Bukhara Massacre of 593 A.H. [1198 A.D.]. 6. Those who wrote various riwayas about a matter in an order with respect to their reliability were called muqallids. They did not include any refused riwaya in their books. Abu 'l-Barakat 'Abdullah ibn Ahmad an-Nasafi (d. 710 A.H.), the author of Kanz ad-daqaiq; 'Abdullah ibn Mahmud al-Musuli (d. 683), the author of Mukhtar; Burhan ash-Sharia Mahmud ibn Sadr ash-Sharia 'Ubaid-Allah (d. 673), the author of Al-wiqaya; and Ibn as-Sa'ati Ahmad ibn 'Ali al-Baghdadi (d. 694), the author of Majma' al-bahrain, are of these (rahmat-Allahi ta'ala 'alaihim ajmain). 7. They are also muqallids incapable of distinguishing weak riwayas from genuine ones.
