John Calvin Commentary 2 Corinthians 12:13

"For what is there wherein ye were made inferior to the rest of the churches, except [it be] that I myself was not a burden to you? forgive me this wrong." — 2 Corinthians 12:13 (ASV)

What is there in which. Here is an aggravation of their ingratitude: first, that he had been distinguished so that they might receive benefit; and second, that though they had profited from the evidence of his apostleship, they had nevertheless supported the slanders of the false apostles.

He adds one exception—that he had not been burdensome to them; and this is stated with irony. For in reality, this was in addition to the many acts of kindness he had shown them, not least that he had served them free of charge. For them to then busy themselves, as they did, with pouring contempt on him—what was this but an insult to his modesty? Indeed, what cruelty this showed! Therefore, not without good reason, he sharply reproves such frantic pride. Forgive me this wrong, he says.

They were, in fact, doubly ungrateful, since they not only despised the man to whom they were indebted for acts of kindness, but even turned his kind disposition into a cause for reproach. Chrysostom believes that no irony is implied here and that, instead, it is an expression of apology; but anyone who examines the entire context more closely will easily perceive that this interpretation is quite contrary to Paul’s intention.