Kitab al-Muʾmin authored by the distinguished 3rd century Shīʿī scholar and narrator, al-Ḥusayn b. Saʿīd al-Ahwāzī, is an influential text within Shīʿī literature. Comprising 201 traditions, this book offers detailed insights into the nature of Belief (Īmān) and the Believers (Muʾminūn), drawing upon the teachings and traditions of the Ahl al-Bayt (as). The most significant feature of this work is its earliness, considering the fact that al-Ḥusayn b. Saʿīd was from amongst the companions of the Imams al-Riḍā, al-Jawād and al-Hādī (as). The central themes the book explores include the understanding of the afflictions a believer endures, the unique honours that Allah bestows upon the believers, and the special bond that exists among the faithful. Furthermore, it discusses the rights that believers hold over each other and the spiritual rewards that accompany acts of kindness towards fellow believers. It also emphasises the importance of social interaction among believers, such as paying visits during illness or in a social context, and the virtues of helping a believer in need, be it by providing food, clothing, or assistance with debts. In summary, Kitab al-Muʾmin is a vital resource for understanding the principles of Iman, the characteristics of a believer (Muʾmin), and the intricacies of interactions within the Muslim community based on the traditions of the Ahl al-Bayt (as).