"He who is waiting yonder leads me here, Whom in disdain perhaps your Guido had"

(Canto 10, lines 62-63)

An ambiguous reference debated through the years. It could either refer to Virgil, in which case it is suggested that Guido would have refused to come with Virgil, or to Beatrice and the theology she represents. In some way, it is perhaps likelier that Dante would take a jab at Guido's supposed "heresy" than suggesting that his poet colleague "disdained" Virgil - on the other hand, Dante does say "he" here, not "she"...