1 Corinthians 5:3

Have already judged, decreed, and do decree, being present in spirit with you, and with your congregation. --- In the name....with the power of our Lord Jesus, to deliver such a one to Satan by a sentence of excommunication, depriving him of the sacraments, the prayers, and communion, and even of the conversation of the rest of the faithful. It is likely in those times, such excommunicated persons were delivered over to Satan, so as to be corporally tormented by the devil, to strike a terror into others. See St. John Chrysostom, hom. xv. and this is said to be done for the destruction, or punishment of the flesh, that the spirit, or soul, may be saved. (Witham) --- It is the opinion of most of the Greek fathers, that this man was either really possessed by the devil, or at least struck with such a complaint as a mortification, and humiliation to his body, whilst it served to purify his soul. We have seen from many instances in holy Scripture, that it was not unusual, in the origin of Christianity, for persons who had fallen into crimes of this nature, to be punished with death, some grievous sickness, or by being possessed by the devil, so as to be separated from the communion of the Church. (St. Ambrose; Estius; Just. [St. Justin Martyr?]; Menochius)