The Epistle of Paul the Apostle to Philemon is a personal letter in which the apostle beseeches Philemon to take back a runaway slave, Onesimus. The slave had come to Rome, where Paul was being held prisoner, and there had been converted by Paul.

Philemon 1

1:13 Whom I would have retained with me, that in thy stead he might have ministered unto me in the bonds of the gospel: