Albert Barnes Commentary Philemon 1:20

"Yea, brother, let me have joy of thee in the Lord: refresh my heart in Christ." — Philemon 1:20 (ASV)

Yes, brother, let me have joy from you in the Lord. "By showing me this favour in receiving my friend and brother as I request." The phrase "in the Lord" here seems to mean that if this request were granted, he would recognise the hand of the Lord in it and would receive it as a favour from him.

Refresh my bowels in the Lord. The bowels, in the Scriptures, are uniformly spoken of as the seat of the affections—meaning commonly the upper viscera, which includes the heart and the lungs. (See Barnes on Isaiah 16:11).

The reason is that in any deep emotion, this part of our body is peculiarly affected, or we feel it there. Compare Robinson's Lexicon on the word splagcnon. See this illustrated at length in Sir Charles Bell's "Anatomy of Expression," page 85 and following (London edition, 1844).

The idea here is that Paul had such a tender affection for Onesimus as to give him great concern and uneasiness. The word rendered "refresh"—anapauson—means to give rest, to give repose, or to free from sorrow or care. The sense is that by receiving Onesimus, Philemon would cause Paul's deep and anxious feelings to cease, and Paul would be calm and happy. (Compare Barnes on Philemon 1:7).