Philemon is nowhere else named in the New Testament. This epistle being sent by Onesimus at the same time as the Epistle to the Colossians seems to intimate that Philemon resided somewhere in the same district. The salutations also being similar in both epistles leads to the conclusion that both were sent from Rome about A.D. 62.
Though “the assembly” in his house is named in Philem. 2, the epistle is written to Philemon and his wife, but doubtless counting on the fellowship of the assembly in the gracious reception of Onesimus.
The occasion is that Onesimus, being a run-away slave, had been converted under Paul's preaching, and is now sent back to Philemon, his master, not now as a slave merely, but as a brother beloved. Paul does not demand or ask for the freedom of Onesimus, for Christianity did not come to set the world right; but he did press that the slave should now be counted a brother, and indeed be received as Paul's “own bowels”. Paul did not assert any apostolic authority, but entreated as Paul the “prisoner” and “the aged”.
To ask an injured master to receive back his runaway slave in grace was a delicate subject, but Paul, led by the Spirit, skillfully words the epistle, and meets every difficulty. If the slave had robbed his master, Paul would repay it; but he then reminds Philemon of how much he himself owed him, even his “own self besides”.
The grace of Christ enters into domestic matters, and elsewhere into the relations of masters and their slaves; for the “servants” referred to in this connection in the various epistles were mostly slaves.