This is a valuable compilation by Abū Ja'far, Muhammad son of Ya'qūb, Kuleinī Rāzī, one of the most brilliant Ulamā of Shi'a in the beginning of the 4th century Hegira.
Al-Kāfī includes a collection of narrations about Usūl and Forū-id-dīn' (primary and secondary principles of religion), which are narrated from the infallible Imāms (A.S.).
By traveling to different cities and villages of the vast Islamic country, and meeting the narrators of Hadīths (traditions), Sheikh-e Kuleinī succeeded to collect the 400 principles of Shi'a', which were transcribed by the disciples of the infallible Imāms (A.S.). He also contacted Nuwwāb-e Khāss (the specified representatives) of the occulted Imām (Imām-e Asr Mahdī AJ.F.), and finally compiled Al-Kāfī, which is a precious collection and an authentic and comprehensive book.
Al-Kāfī is one of the most ancient and authentic books of Riwāyāt' (narrations) of Shi'a, which is compiled at the time of Ghaybat-e Sughrā (minor occultation of the holy Imām Mahdī, may Allāh hasten his reappearance). This book has been written by one of the most significant narrators and jurisprudents of Shi'a (Sheikh-e Kuleinī). The book has been peerless up to the time being, and has continuously received the most special attention of Ulamā and jurisprudents of Islām during past Islāmic millennium, and the great scholars of Shi'a have selected it as a reliable reference book for their own compilations. This book consists of narrations and Hadīths of the holy Prophet (S.A.) and his infallible household (Ahl-ul-Bayt A.S.), in which the Islamic knowledge and precepts have been presented in the best possible form and beautiful order.From the compilation point of view, there has been a short gap between Al-Kāfī and reliable original sources of Shi'a; moreover, it is an anthological work enjoying high accuracy.
Sheikh-e Mufīd cites: "Al-Kāfī is one of the most glorious and most useful books of Shi'a."Shahīd-e Awwal, Muhammad Ibn-e Makkī cites: "Al-Kāfī is a unique book in the field of Riwāyāt (narrations).Feidh-e Kāshānī cites: "Al-Kāfī is the most brilliant, most trustworthy, most perfect, and most comprehensive book among the four authentic resources of Fiqh (Shi'a jurisprudence), because despite other three resources it contains not only the different branches of Fiqh and secondary principles of Islām (Forū'-id-Dīn), but also comprises its primary principles (Osūl-id-Dīn); moreover, it excludes every undocumented, weak, or incorrect Hadīth (narration)".Shahīd-e Thānī states: "Al-Kāfī is a pure, sweet fountainhead. I swear by my own soul that a counterpart of it has not been written. By reading this book, we can find out the dignity and magnificence of its compiler." Allāmah Majlesī says: "Al-Kāfī is the most codified and comprehensive book of narrations, and the best and greatest compilation of the righteous sect of Shi'a."
Sheikh-e Kuleinī has compiled this book upon request of one of his companions. At the opening of the book, he addresses the requester: "Oh, my dear brother! You have mentioned that, some religious subjects are questionable for you, and you do not recognize the fact because of many different narrations about one single subject, and you understand that these differences are resulted from the variety in their origins and sources, and you cannot find anyone reliable with whom you may discuss these subjects. You have also stated that, you would like to have a complete book comprising the whole knowledge and precepts of our religion; a book, which would be sufficient for the students and act as a reference for the scholars. From such a book, which will be based on the trustworthy narrations of Sādiqain (the two honest men, i.e. Imām Bāqir and Imām Sādiq A.S.) and authentic traditions of the holy prophet of Islām (S.A.), one could gain the knowledge of religion and perform his divine mandatory duties accordingly. You have further hoped that under the assistance and patronage of Allāh the Almighty - such a book would be a reference book for guidance of our religious brothers, and all followers of Ahl-ul-Bayt (A.S.). I express my thanks to Almighty Allāh, who guided me, to write the book you had asked for. I hope you find it as you had expected. If you find some shortcomings therein, you must know that I have not neglected the performance of my duties. I believe that goodwill and benevolence towards my Muslim brothers and the followers of the righteous path is an obligation. I hope that we will share the Thawāb' (divine rewards) with those who will learn and put it into action, till the Day of Judgment.
1- the most significant feature of this book is that its compiler has been contemporary to Nuwwāb-e Khāss (the specified representatives of the occulted Imām Mahdī, may Allāh hasten his reappearance), and had a close communication with them, especially because of his residence in Baghdād, where the four representatives lived. It is also noteworthy that Kuleinī passed away in the same year that Alī son of Muhammad Samurī the last specified representative of Imām Mahdī (AJ.F.) passed away.
2- Sheikh-e Kuleinī obliged himself to mention the chain of documentations of all narrations up to the infallible Imāms (A.S.), who were the main source, and this feature adds to the authenticity and value of the book.
3- All narrations is this book have respectively been arranged in the order of their rank, i.e. the firstly- mentioned narrations enjoy a higher rank of authenticity and credibility than the ones coming afterwards.
4- Al-Kāfī comprises the whole Islamic knowledge and precepts, which are narrated from the infallible Imāms (A.S.) and Sheikh-e Kuleinī collected them. It covers most of the Islamic jurisprudential and ideological articles.
Al-Kāfī consists of more than 16,000 narrations, which exceeds even the total number of narrations in Sihāh-e Sittah' (the six reference books of Sunni' jurisprudents).
There are some explanatory books for Al-Kāfī written by other Islamic scholars:
1- Jāmi'-ul-Ahādīth Wal-Aqwāl', by Sheikh Qāsim son of Muhammad son of Jawād son of Alwandī (died after 1100 Hegira)
2- Al-Durr-ul-Manżūm Min Kalām-il-Ma'sūm', by Sheikh Alī son of Muhammad son of Hasan son of Zaynuddīn Shahīd Thānī' (died in 1104 Hegira)
3- Sharh-e Mullā Sadrā Shīrāzī' (Explication of Mullā Sadrā)
4- Mir'āt-ul-Uqūl Fī Sharh-e Akhbār-e Āl-e Rasūl', written by Allāmah Majlesī (died in 1110 Hegira)
5- Al-Wāfī', by Feyz-e Kāshānī (died in 1091 Hegira)
Some of the marginal explanatory notes of Al-Kāfī are as follows:
1- Hāshīah (Annotation) of Allāmah Majlesī
2- Hāshīah (Annotation) of Abul-Hasan Sharīf Fatūnī Āmelī (died in 1138 Hegira)
3- Hāshīah (Annotation) of Sayyid Mīr Abū Tālib son of Mīrzā Beyk Fendereskī, an Islamic scholar of early 12th century Hegira
4- Hāshīah (Annotation) of Sheikh Zaynuddīn Abul-Hasan Alī son of Sheikh Hasan Sāhib-ul-Ma'ālim
5- Hāshīah (Annotation) of Sheikh Muhammad son of Hasan son of Zaynuddīn Shahīd Thānī (known as Sheikh Muhammad Sibt-e Āmelī, died in 1030 Hegira)
1- Tuhfat-ul-Awliā', by Muhammad Alī son of Hāj Muhammad Hasan Ardakānī
2- As-Sāfī, Sharh-e Usūl-e Kāfī Wa Sharh-e Forū'-e Kāfī', by Sheikh Khalīl son of Ghāzī Qazwīnī
Muhammad Ja'far son of Muhammad Safī Nā'esī Fārsī has summarized Al-Kāfī.
There are many research books on Al-Kāfī:
1- Romūz-ut-tafāsīr-ul-Wāqi'ah Fil-Kāfī War-Rawdha'
by Mawlā Khalīl son of Ghāzī Qazwīnī
2- Jāmi'-ur-Ruwāt', by Hāj Muhammad Ardabīlī (a pupil of Allāmah Majlesī)
3- Al-Fawā'id-ul-Kāshifah', by Ayatollah Muhammad Husain Tabātabāee Tabrīzī
4- Al-Bayān-ul-Badī'a, by Sayyid Hasan Sadr
5- Rijāl-ul-Kāfī', by Ayatollah Sayyid Husain Tabātabāee Borūjerdī
1- A manuscript of Al-Kāfī is available in the treasury of Ayatollah Mar'ashī Najafī's library in Qum. The date of writing has been 1071 Hegira; this copy has been read in the presence of Allāmah Majlesī.
2- Another manuscript of Al-Kāfī is being kept in the treasury of Ayatollah Mar'ashī Najafī's library in Qum whose date of writing has been 1092 Hegira, and there are a number of annotations by Sheikh Horr-e Āmelī on this copy.
3- Finally a third manuscript of Al-Kāfī is being kept in the treasury of Ayatollah Mar'ashī Najafī's library in Qum. This copy has been compared with other copies, and corrected. There are many annotations extracted from explication of Mawlā Sālih Māzandarānī - on this copy.