Commentary Inf XXVII 106-111

Silence as a defensive weapon against this pope was probably the only way out; but his imposing insistence was too much for Guido, and he makes his bargain.

A continuing debate follows verse 110. Did Dante read these words in chroniclers who preceded him (e.g., Riccobaldo of Ferrara, Francesco Pipino of Bologna, both of whom wrote before 1313, if we are not sure exactly when), or did they get them from Dante? For the key texts in the dispute see DDP Singleton.Inf.XXVII.67. Some contemporary commentators (e.g., DDP Bosco.Inf.27.Nota) favor the precedence of Riccobaldo's chronicle, perhaps written between 1308 and 1313, and believe that Dante's account (and revision of his former positive view of Guido) derive from it.