John Chrysostom

"For though I should glory somewhat abundantly concerning our authority which the Lord gave for building you up, and not for casting you down, I shall not be put to shame." For since he was going to say somewhat great, observe how he softens it. For nothing doth so offend the majority of hearers as for any one to praise himself. …

Homily 22 on 2 Corinthians ↗

Theophylact of Ohrid

He did not say: I have the authority to punish and put to death, while they do not, but humbly: "even if more." And he did not say: if I boast, but: "if I were to boast," that is, if I wish, he says, to boast about the authority "which the Lord gave us," again attributing all this to the Lord. And I received it from God in order to strengthen in the faith, by doing good, not by punishing. So why did you say: "we demolish schemes"? Because building up consists precisely in tearing down everything rotten and destroying obstacles. …

Commentary on 2 Corinthians ↗

Thomas Aquinas

Then when he says, For even if I boast, he pursues his cause. But it sometimes happens that a person is moved against someone because the former is deceived by the authority of someone who gives himself out as being great. This is the way the Corinthians, deceived by the false apostles who claimed greater authority than Paul, were stirred up against him, because they had come from Judea and were among the first converts. Therefore the Apostle does two things. …

Commentary on 2 Corinthians ↗