This thesis offers an analysis of the Arabic Commentaries on the Hippocratic Aphorisms (9th-15th centuries AD) on three levels, (i) translation, (ii) individual styles and (iii) genre. It particularly examines meta-discursive features such as cohesion, subjectivity, hedges, the addressing of readership, and the formulation of truth statements. The analysis of these features reveals rhetorical conventions in the corpus that indicate a discursive unity of the genre of the medieval medical commentary. Yet, this study also shows considerable stylistic variation between the individual commentators which, besides its intrinsic value, is crucial for the identification of these authors' texts. Moreover, this research examines how the rhetorical features of the later commentaries have developed after the fashion of Ḥunayn Ibn Ishaq's 9th-century translation of Galen's 2nd-century Greek commentary. This study highlights significant differences between Ḥunayn's rhetorical strategies and those in the later Arabic commentaries. Thus, this work demonstrates discontinuities between Greek and Arabic medical discourses, despite the huge influence of Ḥunayn's translation.This thesis uses an innovative quantitative methodology combining both close reading and distant reading techniques to study Ḥunayn's translation technique, and compare Ḥunayn's style with that of the later commentators. Furthermore, this study advances the understanding of the ways of writing in scientific medieval Arabic. Finally, the separate studies in this thesis contribute knowledge regarding grammatical phenomena such as modals, conjunctions, and conditionals in Classical Arabic.