Yet for love's sake I rather beseech you, being such a one as Paul the aged, and now also a prisoner of Jesus Christ.
All Commentaries on Philemon 1:9 Go To Philemon 1
Ambrosiaster
AD 400
Paul makes an appeal for him. Philemon was about the same age as Paul and also a 'prisoner' of Jesus Christ, which means that he was obliged to do the Lord's buisness or even subject to imprisonment on account of the name of Christ, as the apostles themselves also were.