John Calvin on 2 Corinthians 7:14

14. But if I have boasted any thing to him. He shows indirectly, how friendly a disposition he had always exercised towards the Corinthians, and with what sincerity and kindness he had judged of them; for at the very time that they seemed to be unworthy of commendation, he still promised much that was honorable on their behalf. Here truly we have a signal evidence of a rightly constituted and candid mind, — reproving to their face those that you love, and yet hoping well, and giving others good hopes respecting them. Such sincerity ought to have induced them not to take amiss any thing that proceeded from him. In the mean time, he takes this opportunity of setting before them again, in passing, his fidelity in all other matters. “You have hitherto had opportunity of knowing my candor, so that I have shown myself to be truthful, and not by any means fickle. I rejoice, therefore, that I have now also been found truthful, when boasting of you before others.”