And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure.
All Commentaries on 2 Corinthians 12:7 Go To 2 Corinthians 12
Tertullian of Carthage
AD 220
The right to tempt a man is granted to the devil … whether God or the devil initiates the plan or for the purpose of the judgment of a sinner, who is handed over to the devil as to an executioner. This was the case with Saul. “The spirit of the Lord departed from Saul, and an evil spirit from the Lord troubled and stifled him.” Again, it may happen in order to humble a man, as St. Paul tells us that there was given to him a thorn, a messenger of Satan, to buffet him, and even this sort of thing is not permitted for the humiliation of holy men through torment of the flesh, unless it be done so that their power to resist may be perfected in weakness. The apostle himself handed Phigellus and Hermogenes over to Satan so that by being chastised they might not blaspheme. And so you see that, far from possessing power in his own right, the devil can more easily be granted it by the servants of God.