Albert Barnes Commentary 2 Corinthians 10:11

"Let such a one reckon this, that, what we are in word by letters when we are absent, such [are we] also in deed when we are present." — 2 Corinthians 10:11 (ASV)

Let such an one think this, etc. Let them not flatter themselves that there will be any discrepancy between my words and my deeds. Let them feel that all that has been threatened will certainly be executed, unless there is repentance.

Paul here deliberately contradicts the charge that was made against him; and means to say that all that he had threatened in his letters would certainly be executed, unless there was reform. I think that the evidence here is clear that Paul does not intend to admit that what they said about his bodily presence was true; and most probably all that has been recorded about his deformity is mere fable.