'Buffet' in the Bible

But [like a boxer] I strictly discipline my body and make it my slave, so that, after I have preached [the gospel] to others, I myself will not somehow be disqualified [as unfit for service].

Because of the surpassing greatness and extraordinary nature of the revelations [which I received from God], for this reason, to keep me from thinking of myself as important, a thorn in the flesh was given to me, a messenger of Satan, to torment and harass me—to keep me from exalting myself!