eliseroelands says:
That's from Dante.

"If I believed that my response were
to a person who would ever return to the world
this flame would stay without ever moving.
But because from this abyss
No one ever returns alive, if I hear the truth,
without fear of infamy I can respond to you."

This is from where Dante gets to the more intense levels of hell. Up until then he could go up to sinners and ask them what they had done, and most of them would answer because he would make them famous on earth ("woohoo! i'm the best thief ever!!") But as he gets further into hell, dealing with worse sins (which according to Dante are betraying your country/family/benefactors), the sinners he meets are less eager for fame and need a little persuasion to talk. Since this sinner believes that no alive person is walking around in hell, he can tell Dante what he did because he thinks no one on earth will ever hear it.

Hope that helps.