"Kumayl bin Ziyad" is a detailed biography of one of the most devoted companions of Imam Ali (AS), known for his deep knowledge, unwavering faith, and spiritual excellence. He is best remembered for transmitting the renowned Dua Kumayl, a supplication filled with profound expressions of humility, repentance, and devotion to Allah (SWT). This book explores Kumayl’s close relationship with Imam Ali (AS), his role in preserving the teachings of the Ahlul Bayt (AS), and his steadfastness in the face of tyranny. Despite persecution under the oppressive rule of Hajjaj ibn Yusuf, Kumayl remained committed to his faith until his martyrdom. His life serves as an inspiration for those seeking knowledge, sincerity, and devotion to divine leadership.