Taking the qurʾānic crucifixion (Q 4:157-158) as a case study, this paper lays out an approach to analyzing the rhetorical and linguistic features of qurʾānic prooftexting by Syriac- and Arabic-speaking Christians from the eighth to the eleventh centuries. Building on the author's monograph on these verses in early Muslim-Christian polemics (De Gruyter, 2025), the presentation will examine categories of active and passive engagement with the Qurʾān based on close textual analysis. These include changes to core formulas of faith ('creedal' statements) that reflect the ongoing christological controversies among the Eastern churches, the influence of the Qurʾān's theological vernacular, and Christian awareness of early Islamic tafsīr.