St. John Chrysostom says: "The progress of disciples is, for a wise teacher, life, consolation, and delight. Great is the praise when the teacher boasts and rejoices that his praise proves true. For he says: I was not put to shame.
He rejoiced not so much because Titus received such honor from the Corinthians, as because they showed such affection toward Titus. But lest anyone think he rejoiced more on Titus' account, see how here also he sets forth the cause of his joy.
As he said above, 'If I boasted of you to him in anything, I was not put to shame,' so now he says, 'I have confidence in you in all things.' If I must rebuke you, I do not fear that you will be grieved by it. If I must boast of you, I am not afraid.
I said, 'Cut him off,' and you cut him off. I told Titus that you are great, worthy of admiration, and know how to honor teachers. You proved this in deed beyond what I had told him."