Commentary Purg IX 85

The warder's words of challenge, 'Dite costinci' (Say it from there) repeat, as many note, the challenge of one of the centaurs to the approach of Virgil and Dante ([Inf XII 63]) and, like that one, probably reflect Charon's similar words (fare age... iam istinc [tell me... right where you are]) to the invading Aeneas in Aeneid. VI.389, as Daniello (DDP Daniello.Purg.IX.85-87) was perhaps the first to note.