John Chrysostom

"For what is there wherein ye were made inferior to the rest of the Churches?" 'Ye were partakers,' he says, 'of no less grace than the others.' But perhaps some one will say, 'What can be the reason that he turns the discourse upon the Apostles, abandoning the contest against the false Apostles?' Because he is desirous to erect their spirits yet further, and to show that he is not only superior to them, but not even inferior to the great Apostles. …

Homily 27 on 2 Corinthians ↗

Theophylact of Ohrid

Lest anyone should say: true, you are great, but still you have not done what the apostles did in other churches, therefore he says: what do you lack? Did you receive a lesser gift compared to the other churches? He rebukes them with great severity, saying: if you hold it against me that I did not burden you, but preached the Gospel to you without putting you to any expense, then I ask for indulgence; forgive me this fault. …

Commentary on 2 Corinthians ↗

Thomas Aquinas

Then he excludes an objection, when he says, For in what were you less favored than the rest of the churches? For the Corinthians could answer and say: it is true that you have done many good and great things, but others have done more and greater things than you. Therefore, we are not willing to commend you to them or in comparison with them. But he excludes this, saying: For in what were you less favored than the rest of the churches? i.e., than the other churches of Christ have obtained through him in spiritual matters. …

Commentary on 2 Corinthians ↗