Abu Bakr Qaffal ash-Shashi studied law from such respectable experts as historian Abu Ja’far Muhammad ibn Jarir at-Tabari (died in 923), Abu Bakr ibn Khuzayma (died in 933), Abu Bakr Muhammad al Baghandi, Abu Zayd al-Marvazi and others.
A well-known historian Abu Sa’d Sam’ani states that Abu Bakr Qaffal ash-Shashi visited Khorasan, Iraq, Hijaz, Syria and Sughur (Northern Syria) in search of knowledge and enlightenment. There his teachers and tutors were such estimated scholars as Abu Bakr Muhammad ibn Is’haq ibn Khuzayma, Abul Abbas Muhammad ibn Is’haq as-Sarraj, Abulqasim Abdullah ibn Muhammad al-Baghavi and Abu Aruba al-Husain ibn Tilab al-Mashgharai.
Into the class of Qaffal ash-Shashi’s students and followers, we may include a well-known scientist of his time Abu Abdullah al-Halimi (339/950-430/1012), who lived in Jurjan, Bukhara and Nishapur and was one of the leaders of experts in the science of Hadiths and worked as a judge in different cities of Maveraunnahr. In his book “Shua’b al-Iman” (Constituent Parts of Iman (Faith)), he characterized his beloved teacher Abu Bakr Qaffal ash-Shashi as “an incomparable genius among the scholars of his time”. The other followers of Qaffal ash-Shashi were Abu Sulayman al-Busti (died in 388/998), who had written commentaries on the book “Musnad” by Abu Davud (202/817-275/888), the author of the book “Events taken place in Nishapur” Abu Abdullah al-Hakim an-Nisaburi (died in 405/1014), the author of the book “The description of the representatives of Sufism” Abu Abdurrahman as-Sulami (died in 412/1021) and Ibn Mandah. Among the lawyers who were devoted to the ideas of Qaffal ash-Shashi we can mention the names of Abu Abdurrahman al-Ibrisami, Abu Is’haq ash-Shashi, Nasir ibn al-Husain al-Marvazi and Abu Nasr Umar ibn Qatada. Abu Bakr al-Qaffal ash-Shashi not only studied and investigated the secrets of the Islamic sciences when he visited foreign countries but also, in his turn, taught the secrets of these sciences to his students and followers. Therefore, he became a world famous genius in this field.
As to the scientific legacy of Abu Bakr al-Qaffal ash-Shashi, during our studies we have discovered nine works of the author. Two of them are commentaries on the works written by other authors, one of which is a commentary written on a famous book in the Islamic world “Ar-Risala” (A Monograph) by Imam Shafi’i. The second one is a commentaiy written on the book “At-Talhis fi-l-furu” (Shortenings in Furu) by Abulabbas Ahmad ibn Yaqub ibn Al-Qas at-Tabari (died in 335).
Foreign historical sources inform us about the peculiarities of the works written by Abu Bakr al-Qaffal ash-Shashi. “There are lots of works written by Abu Bakr al-Qaffal ash-Shashi that nobody else has ever written such a number of works”, wrote Sheikh Is’haq ash-Shirazi, “he was the first among the lawyers to have written a book about “Al-Jadal al-Hasan” (A Good Debate). Alongside with them, he also wrote books in the field of law such as “Kitab fi usul al-Fiqh” (Foundations of Law) and “Sharh ar-Risala” (A Commentary of the Monographic Research)”.
It is well known that Imam Abu Abdullah Muhammad ibn Idris ibn Abbas ash-Shafi’i (767-820) made a considerable contribution to the development of the science of law. His books in this field “Ar-Risala” and “Al-Umm” are very famous in the Islamic world.
As Hajji Khalifa conforms, Imam Shafi’i’s book “Risala ash-Shafi’i fi-l-fiqhi a’la mazhabihi” (A Monographic Research Made by Ash-Shafi’i about the Law of His Order) was very famous among the lawyers and some of the experts in this field organized debates about the essence of this book. This book was commented on by such experts as Abu Bakr Muhammad ibn Abdullah ash-Shaybani an-Nisaburi (died in 388), Abulvalid Hasan ibn Muhammad al-Qurayshi al-Umavi (died in 349) and Imam Abu Bakr Muhammad ibn Ali al-Qaffal al-Kabir ash-Shashi (died in 365).
Alongside with them, there is a book titled as “At-Talhis fi-1-furu” (Shortenings in Furu) written by Abulabbas Ahmad ibn Muhammad ibn Yaqub ibn al-Qas at-Tabari ash-Shafi’i (died in 335). In spite of its small size, this book contains necessary styles and furu in the field of law. There are some commentaries written by different authors among which Qaffal ash-Shashi’s commentaries are of most noticeable.
According to the information mentioned in the works of Imam an-Navavi, there are some important works written by Abu Bakr Qaffal ash-Shashi. First of all, he wrote a book on the scientific debates in law titled as “Al-Jadal al-Hasan” (A Good Debate). This idea is also confirmed by Imam an-Navavi that Qaffal ash-Shashi was the first scholar to have written a book on debates. According to the opinion expressed by Sheikh Abu Is’haq in his book “Tabaqat”, no one else had ever written so many books as had done Qaffal ash-Shashi. A book titled as “Usui al-fiqh” (Styles in Law) and a commentary on Imam Shafi’i’s “Risala” were also written by Imam Abu Bakr Qaffal ash-Shashi.