Muhammad ibn al-Munawwar's 'Secrets of Monotheism in the Stations of Abu Sa'id' is an indispensable masterpiece of classical Sufi literature. This profound work serves as the most comprehensive and authoritative biography of the renowned 10th-century Persian Sufi master, Abu Sa'id Abu al-Khayr. Penned by his great-grandson, the book meticulously chronicles Abu Sa'id's spiritual journey, his profound mystical experiences, practical teachings, and illuminating anecdotes. It offers invaluable insights into the daily life of a Sufi khanqah and the evolving practices of early Khurasani Sufism, making it essential for scholars and spiritual seekers alike.