8 Therefore, though I might be very bold in Christ to command you what is fitting,
9 yet for love’s sake I rather appeal to you—being such a one as Paul, the aged, and now also a prisoner of Jesus Christ—
10 I appeal to you for my son Onesimus, whom I have begotten while in my chains,
11 who once was unprofitable to you, but now is profitable to you and to me.
12 I am sending him back. You therefore receive him, that is, my own heart,
13 whom I wished to keep with me, that on your behalf he might minister to me in my chains for the gospel.
Paul is making a gracious plea for Onesimus. He is coming to the purpose of his letter. He approaches his subject diplomatically and cautiously and lovingly. He is going to make his request for Onesimus on a threefold basis:
“For love’s sake.” This is the love of Paul and Philemon for each other as believers in Christ Jesus.
“Being such an one as Paul the aged.” Paul was only in his sixties, but he was an old man. He had suffered and had been persecuted as a missionary for Christ. This had aged him. Paul says to Philemon, “You know that I am an old man now.”
“A prisoner of Jesus Christ.” It is evident that he could not come to Philemon in person.” — McGee, page 187.
Therefore (v.8) — referring back to what Paul said about Philemon’s love and faith in vs.5-7.
in Christ (v.8) — the source of Paul’s authority as an apostle
appeal (v.9) — Paul chose not to exercise his apostolic authority; instead, he chose the path of love and grace and left the matter up to Philemon. — Grace, page 2167.
whom I have begotten (v.10) — Paul led Onesimus to Christ.
This verse (v.11) contains a play on words. The name Onesimus means “useful” or “profitable.” Paul is saying that Onesimus had previously not lived up to his name, but now (since his salvation) he will not only be useful to Philemon, but already has proven himself such to Paul. — KJV Commentary, page 1667.
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