This paper examines the tradition of rhetorical exegesis on technical works – namely on Hermogenes’ treatises – flourished from the third century AD onwards. A focus on the evidence preserved proves the exegetes’ preference for the commentary format and the significant similarities in the structure and arrangement of the material with other exegetical literature of the same period. Moreover, by discussing further the content and scope of these commentaries, their relationship with teaching practice will be argued.