John Wesley on 2 Corinthians 12:7

There was given me - By the wise and gracious providence of God. A thorn in the flesh - A visitation more painful than any thorn sticking in the flesh. A messenger or angel of Satan to buffet me - Perhaps both visibly and invisibly; and the word in the original expresses the present, as well as the past, time. All kinds of affliction had befallen the apostle. Yet none of those did he deprecate. But here he speaks of one, as above all the rest, one that macerated him with weakness, and by the pain and ignominy of it prevented his being lifted up mere, or, at least, not less, than the most vehement head ache could have done; which many of the ancients say he laboured under. St. Paul seems to have had a fresh fear of these buffetings every moment, when he so frequently represses himself in his boasting, though it was extorted from him by the utmost necessity.