IʿJĀZ is the concept of the "miraculousness of the Qurʾān." That the Qurʾān is the miracle of Muḥammad is an Islamic doctrine of the utmost importance because it is held to prove the divine source of the holy Book, and hence its authority, as well as the authenticity of the Prophet to whom it was revealed. But what constitutes this miracle is a subject that has engaged Muslim thinkers for many generations. By the early part of the third century AH (ninth century CE), the word iʿjāz had come to mean that quality of the Qurʾān that rendered people incapable of imitating the Book or any part thereof in content and form. By the latter part of that century, the word had become a technical term, and the numerous definitions...