Fath al-Mulhim bi-Sharh Sahih al-Imam Muslim (Arabic: فتح الملهم بشرح صحيح الإمام مسلم) is a three-volume Arabic commentary on Sahih Muslim, written by Shabbir Ahmad Usmani before 1916. Usmani commenced the writing of the book in 1914 due to the absence of commentaries on Sahih Muslim, unlike Sahih al-Bukhari, which had commentaries according to the Hanafi school. He dedicated himself to bridging this gap and continued his work until his demise.^[1][2] He was only able to complete three volumes of the book before his passing. The first and second volumes were published in 1933 and 1935 respectively, while the third volume was published in 1939.^[3] Taqi Usmani later took up the task of completing the remaining portions of the book in 1976, ultimately finishing it in 1994 in six volumes known as Takmilah Fath al-Mulhim bi-Sharh Sahih al-Imam Muslim.^[4]

The book is known for its detailed analysis of Hadith and its scientific principles. It begins with a lengthy introductory chapter of 108 pages, where Usmani discusses the rules of Hadith, its sciences, and the uniqueness of Sahih Muslim. He also explores the different types of traditions, qualities of narrators, and the compilation of Hadith, among other related topics. Additionally, Usmani addresses challenging aspects of Hadith, such as the existence and virtues of Allah, the activities of other deities, and their realities. He includes the best and selected comments of experts on each issue and presents his own views supported by various proofs.^[5][6]

The key features and characteristics of Fath al-Mulhim are as follows:^[7][8][9]

1. It carefully addresses controversial issues related to faith within the Ahl al-Sunnah wa al-Jama'ah, minimizing differences.
2. Usmani mentions the famous and significant events of narrators, provides information on unknown narrators, and points out their shortcomings when necessary.
3. He resolves doubts regarding the chains of narrators in specific instances.
4. The book offers analysis and clarification of difficult words found in Hadith.
5. Quotations from famous books related to the subject matter are provided in various places, aiding in comprehensive explanations of the discussed topics.
6. References to books written on the mysteries of Sharia, such as those by Shah Waliullah Dehlawi, Al-Ghazali, are mentioned in specific cases.
7. Usmani consolidates scattered research findings from various lessons in Fath al-Ban and other books, bringing them together in one place.
8. In analyzing and establishing the truth of a lesson, he includes necessary quotations from books of the Hanafi school of thought. He also provides extensive Arabic references to the research of his teachers and the pioneers of the Hanafi school, even if they were originally written or spoken in languages other than Arabic.
9. The book contains numerous research findings that were previously unheard of and are only understood after reading it.
10. Usmani strives to write in clear and accessible language, expressing his own comments alongside the text.
11. He emphasizes the Qur'an as the basis of all traditions.
12. Usmani refutes recent doubts and arguments against Islam in specific instances.
13. The author engages in a thorough investigation of disputed matters related to faith.

Anwar Shah Kashmiri praised Shabbir Ahmad Usmani's knowledge of Hadith literature and stated that nobody has explained Sahih Muslim better than him.^[10] Sayyid Muhammad Khaiid All, a professor at Jamia Millia Islamia, described the book as a comprehensive and simplified explanation of Sahih Muslim that frees readers from having to refer to multiple commentaries.^[10] Jubair Ahmed Faruqi, the head of the Arabic Department at Jamia Millia Islamia, highlighted the book's importance and usefulness, with scholars from across the Islamic world admiring and accepting it. Some even consider it more important than Al-Nawawi's commentary in various aspects.^[10] Syed Abdul Majid Ghouri, a professor at the Universiti Sains Islam Malaysia, commended this book is regarded as one of the best and most comprehensive explanations of Sahih Muslim. He praises the accuracy and meticulousness with which all the Hadiths in each chapter are explained, leaving no issue of jurisprudence without clarification.^[11]

• Deobandi hadith studies