The intellectual legacy of the Baṣrān Muʿtazila has had a profound and lasting impact on the development of discussions on Qurʾānic inimitability. Numerous writings have been composed by Baṣrān Muʿtazila on the topic; among them is Iʿjāz al-Qurʾān by Abū Rashīd al-Naysābūrī, an unpublished manuscript preserved in the King Saud University Library under the number 7752. This paper focuses on the development of al-Naysābūrī’s understanding of Qurʾānic inimitability in the context of this manuscript, especially analysing his reception of early Muʿtazilī (specifically Bahshamī) thoughts on Qurʾānic inimitability. Moreover, it pays particular attention to al-Naysābūrī’s engagement with the critiques directed against the Bahshamī theory of Qurʾānic inimitability. This paper adopts a source-criticism approach to studying the manuscript and evaluating the historical development of its contents. It argues that the theoretical foundation underlying the theory of miraculous eloquence developed by ʿAbd al-Jabbār drew al-Naysābūrī’s attention towards a deep engagement with hypothetical dialogues inspired by the refutations of questions concerning Qurʾānic inimitability posed by the freethinkers’ movement. This engagement prompted al-Naysābūrī to adopt and assess numerous hypothetical frameworks and conditional views, including the ṣarfa theory, in his defence of Qurʾānic inimitability. This approach of addressing the freethinker critiques aligns greatly with the dynamic and responsive nature of Baṣrān Muʿtazila’s thoughts against freethinkers’ movement
