The Gizistag Abāliš is a ninth- or tenth-century Pahlavi text, recording a debate which took place at the court of al-Maʾmūn between a Zoroastrian priest and a heretical dualist. This article, the first in-depth study of this important work, examines the text in its broader Islamicate environment. It argues that the narrative itself is probably fictional, but reflects a real historical phenomenon, namely the interreligious debates which took place among Zoroastrians, Muslims, Christians, and Jews during the ʿAbbasid period. It argues that the text is a unique Zoroastrian example of a literary genre that was common among Christians at the time, namely, "the monk in the emir's majlis." By comparing the Gizistag Abāliš to these Christian texts, it explores why Zoroastrians generally did not launch explicit polemics against Islam, comparable to those of other non-Muslim communities. It seems that Zoroastrian authors were more concerned with explaining their own doctrines than critiquing the beliefs of others. This is curious considering the large numbers of Zoroastrians who were converting to Islam at the time. Finally, the article proposes new ways of refining the way we read Pahlavi texts, by analyzing them alongside the literatures of other religious communities in the early Islamic empire. [ABSTRACT FROM AUTHOR]