37.3.1 (to Marcella; discussing Reticius' commentary on the Song of Songs; my translation):
There are countless things in his commentaries which I thought were paltry. His style, to be sure, is well-ordered and fluent in the high Gallic manner: but what has style to do with a commentator, whose business is not how to make himself appear eloquent, but rather how to make the prospective reader understand the intended meaning of the original writer.
innumerabilia sunt, quae in illius mihi commentariis sordere visa sunt. est sermo quidem conpositus et Gallicano coturno fluens: sed quid ad interpretem, cuius professio est non, quomodo ipse disertus appareat, sed quomodo eum, qui lecturus est, sic faciat intellegere, quomodo intellexit ille, qui scripsit?
49(48).17.7 (to Pammachius; tr. W.H. Fremantle et al.):
A commentator has no business to dilate on his own views; his duty is to make plain the meaning of the author whom he professes to interpret.
commentatoris officium est, non quod ipse velit, sed, quid senitat ille, quem interpretatur, exponere.