John Calvin Commentary 2 Corinthians 12:5

"On behalf of such a one will I glory: but on mine own behalf I will not glory, save in [my] weaknesses." — 2 Corinthians 12:5 (ASV)

Of such a man It is as if he had said, “I have just cause for glorying, but I do not willingly make use of it. For it is more in keeping with my purpose to glory in my infirmities. If, however, those malicious persons harass me any further and compel me to boast more than I am inclined to do, they will learn that they are dealing with a man whom God has illustriously honored and raised up on high, so that he might expose their follies.”