Al-Bustī, who is included in the eleventh generation of the Muʿtazilī ṭabaqāt, was one of the students of Qāḍī ʿAbd al-Jabbār, and received his own theological doctrines from him (al-Ḥākim al-Jishumī, 385–386). By virtue of being one of the qāḍī’s students, he lived in Rayy for several years. It is said that he held a position of considerable prestige under his teacher and Qāḍī ʿAbd al-Jabbār would at times refer questions put to al-Bustī for a response (al-Jundārī, 7; al-Ḥākim al-Jishumī, 385–386).

In 389/999 al-Bustī performed the Ḥajj with Q…