Muqātil b. Sulaymān's work is the oldest surviving exegesis which comments on the entire Qur'ān from the beginning to the end. Analytical comparisons between different manuscripts of this exegesis and the quotations made by the exegetes, who greatly benefited from Muqātil, give us important information about the history of Quranic exegesis. al-Tha ‘labī's references to Muqātil offer valuable data illuminating the role of ‘the changing contents’ of the manuscripts in understanding the history of the exegesis. Changing evaluations and criticism about Muqātil's personality and his opinions show that the history of Quranic exegesis needs to be further critically studied.