Retrieving al-Kafī’s Sources in the Light of the Analysis of the Function of the Common link with Emphasis on the Role of the Common link of Ḥasan ibn Maḥbūb

Introduction
Since the late second century, the study of the reliability of ḥadith among Shi'a traditionists was based more on the bibliographic analysis of ḥadith; that is, the criticism and examination of the ḥadith text based on the book from which it was taken and not on the basis of the chain of transmitters of ḥadith. Over time, and due to the presence of contextual and temporal elements, the approach of Shi'a traditionists changed from bibliographic analysis to Rijāl analysis. The turning point of this change was clearly manifested and emerged in the Rijāl views of Ibn Ţāwūs al-Ḥillī (d. 1274) and Muhaqqiq al-Ḥillī (d. 1277). With the dominance of the Ḥillah school of Rijāl, the status of the Rijāl became the basis for accepting and rejecting ḥadith, and the bibliographical benefits were neglected unconsciously. Regarding these considerations one can understand the importance of identification the sources of early compilatory works for the bibliographic analysis of ḥadith and determining the authenticity and reliability of traditions. Among the early Shi'a ḥadith sources, the identification of the sources of al-Kafī, the earliest book in the collection of the four books of Shi'a ḥadith, is of particular importance. Unlike Sheikh al-Șadūq in Man lā yaḥḍrah al-Faqīh and Sheikh al-Ţūsī in al Taḥdhīb and al-Istibṣār, al-Kulayni neither introduced his sources in the introduction to al-Kafī nor, like Sheikh al-Șadūq and Sheikh al-Ţūsī, did he include a separate section called al-Mashikha for al-Kafī.
 
Materials and Methods
In this article, using a systematic model for retrieving sources of ḥadith texts, which is defined in the form of nine steps based on the role of the common link in the Isnad of traditions, and by providing some points to deepen it, the common links in a group of frequently repeated Isnads of traditions of al-Kāfī, namely Ali ibn Ibrāḥīm from Ibrāḥīm ibn Hāshim from Ḥasan ibn Maḥbūb from Ali ibn Ri'ab from Zurarah, have been identified and their function has been analyzed. These nine steps are: 1. Extracting and categorizing isnads; 2. Determining common links; 3. Identifying common author links; 4. Examining the function of common author links; 5. Ensuring the attribution and title of the book; 6. Comparing texts; 7. Matching methods with the isnad of traditions; 8. Thematic-statistical examination; 9. Examining secondary evidence. The common link refers to a transmitter who is repeated in the Isnads of a collection of traditions of a narrative work (monograph or comprehensive tradition) and who has multiple sheikhs, and therefore there is dispersion and branching after his name in the earlier chain of tradition. The aforementioned definition is based on Sezgin's definition of the common link phenomenon and differs from Schacht's definition of this phenomenon. In order to demonstrate the necessity of paying attention to the branches of the later part of the chain of transmission and the prominent disciples of a transmitter, while paying attention to the branches of the earlier part of the chain of transmission and the teachers of a transmitter in order to retrieve sources, in this study, steps three to nine have been taken under the name of each category of transmitters. With this action, the thematic connection of their works with different parts of the book of al-Kafī is examined, and the possibility of their being a source, a source of a source, or a transmitter for al-Kulayni is examined.
 
Results and Findings
Although the aforementioned method is based on analyzing the function of the common link and paying attention to the transmitter's multiple sheikhs, it is necessary to also pay attention to the students who have quoted a significant number of traditions from him when examining and comparing the subject matter of each category of transmitters with the subject matter of the various chapters and sections of the narrative work. In other words, in addition to paying attention to the branches of the early part of the chain of transmission and the transmitter's sheikhs, attention should be paid to the branches of the later part of the chain of transmission and his students and prominent transmitters. If there were other students other than the student mentioned for the transmitter of the category in question in the branch in question who narrated a significant number of traditions from him, the subject of their traditions and works and compositions should also be considered. A study of the students of the second category, Ibrāḥīm ibn Hāshim, indicates that although there are transmitters such as Muḥammad ibn al- Ḥasan Saffar and Muḥammad ibn Aḥmad ibn Yaḥya who have narrated a handful of traditions from him, almost all of his traditions were narrated by Ali ibn Ibrāḥīm, and therefore, in this category, there is no need to examine the transmitters, students, and branches of the later part of the chain of transmission. But in the case of the third category, namely Ḥasan ibn Maḥbūb, the necessity of considering this new step clearly shows itself because the majority of his traditions in al-Kafī are narrated through Aḥmad ibn Muḥammad ibn 'īsā and not Ibrāḥīm ibn Hāshim. In addition to Ibrāḥīm ibn Hāshim, who narrated about 21 percent of Ḥasan ibn Maḥbūb's traditions in al-Kafī, there ar transmitters like Aḥmad ibn Muḥammad ibn 'īsā Al-Ash'ari and Sahl ibn Ziyad al-Adami, who narrated about 50 and 22 percent of the total traditions of Ḥasan ibn Maḥbūb in al-Kafī, respectively. Although there are other transmitters who have narrated traditions from Ḥasan ibn Maḥbūb, the main focus is on transmitters that a large number of traditions have been transmitted through them, and transmitters who have narrated a small number of traditions can be ignored.
 
Conclusion
Based on the evaluations, four common links of Ali ibn Ibrāḥīm, Ibrāḥīm ibn Hāshim, Hasan ibn Maḥbūb, and Ali ibn Riab were identified in the chain of transmission in question. It is very likely that Ali ibn Ibrāḥīm and Ibrāḥīm ibn Hāshim were the direct sources of al-Kulayni. It is very likely that Ali ibn Ri'ab’s traditions reached al-Kulayni through the works of Hasan ibn Maḥbūb. In fact, in these cases, the works of Ibn Ri'ab were the source of a source for al-Kulayni. Based on the analyses conducted, it can be seriously suggested that al-Kulayni used the works of Hasan ibn Maḥbūb, with the explanation that in cases where he mentions the path of Ali ibn Ibrāḥīm from Ibrāḥīm ibn Hāshim, he mostly used the works of Hasan ibn Maḥbūb through the works of Ali ibn Ibrāḥīm. However, in cases where he attempted to obtain traditions from the works of Hasan ibn Maḥbūb through Muḥammad ibn Yaḥya from Aḥmad ibn Muḥammad ibn 'īsā, she mostly used the traditions of Muḥammad ibn Yaḥya and Aḥmad ibn Muḥammad, rather than their writings.