A foundational work by Abi Abdullah al-Salihi, investigated by Ibrahim al-Zubaiq, this book meticulously categorizes the great scholars of Hadith into different classes or generations. It serves as an essential biographical dictionary for students of Islamic sciences. This 2014 edition, presented with a fine art cover, is a voluminous compilation spanning 1899 pages, detailing the lives, contributions, and statuses of narrators, making it an indispensable resource for understanding the chains of transmission and the history of prophetic traditions.