This work is both an introduction to the genre of classical tafsīr and a detailed study of one of its major architects, al-Thaʿlabī (d. 427/1035). The book offers a detailed study of the hermeneutical principles that governed al-Thaʿlabī's approach to the Qurʾān, principles which became the norm in later exegetical works. It is divided into three main sections; the first outlines the life and times of the author; the second is a detailed study of his major exegetical work, al-Kashf; the third charts a brief history of the genre of tafsīr through documenting the reactions of later exegetes to al-Kashf. This work brings together material never examined before and tries to offer a new way of understanding the history of classical Qurʾān exegesis.