Commentary Inf V 22-24

Virgil obviously understands that Minos's words were meant to scare Dante off (and perhaps he also understands the implicit insult to himself contained in them). For the repetition here of the identical verses (23 and 24) used to quell Charon's rebellious desires see [Inf III 95-96] and C.Inf.III.95-96. It seems clear that Virgil would not have used them again had they not been efficacious the first time, that is, had Charon not relented and rowed Dante across. See C.Inf.III.136.