John Calvin Commentary 2 Corinthians 2:9

"For to this end also did I write, that I might know the proof of you, whether ye are obedient in all things." — 2 Corinthians 2:9 (ASV)

For I had written to you also for this purpose. He anticipates an objection that they might raise. “What then did you mean, when you were so very indignant because we had not inflicted punishment upon him? From being so stern a judge, to become all at once a defender—is not this indicative of a man who wavers between conflicting dispositions?” This idea might detract greatly from Paul’s authority; but he answers that he has obtained what he asked, and that he was therefore satisfied, so that he must now give way to compassion. For, their carelessness having been corrected, there was nothing to hinder their lifting up the man by their clemency, when he was now prostrate and downcast.