This book is the first extensive examination of the medieval Qur’an commentary known as the Latāʾif al-ishārāt (The Subtleties of the Signs), and the first critical biography of its author, the famous spiritual master Abū’l-Qāsim al-Qushayrī. Written in fifth/eleventh century Nishapur, an intellectual and cultural crossroads of the Muslim world, the Latāʾif al-ishārāt commentary exhibits an important confluence of different traditions that are interwoven into Qushayrī’s overarching mystical exegesis. Martin Nguyen fully investigates these various traditions of exegesis, together with Qushayrī’s life and historical horizon, and the hermeneutics of the commentary. The resulting study demonstrates how we can better appreciate Qushayrī and his work within a wider Sunni historical heritage, in addition to the developing Sufi tradition.