The Apostle Paul
Philemon 1:12BSB·traditional attribution

I am sending back to you him who is my very heart.

John Calvin Reformed @genevareformer

12. Receive him, that is, my bowels. Nothing could have been more powerful for assuaging the wrath of Philemon; for if he had refused to forgive his slave, he would thus have used cruelty against “the bowels” of Paul. This is remarkable kindness displayed by Paul, that he did not hesitate to receive, as it were into his bowels, a contemptible slave, and thief, and...

Matthew Henry Presbyterian @wholebiblehenry

We have here, I. The main business of the epistle, which was to plead with Philemon on behalf of Onesimus, that he would receive him and be reconciled to him. Many arguments Paul urges for this purpose, Plm 1:8-21. The 1st Argument is taken from what was before noted, and is carried in the illative wherefore: "Seeing so much good is reported of thee and...

Commenting on Philemon 1:8-25

John Gill Reformed Baptist @doctorgill

Whom I have sent again,.... From Rome to Colosse, or to Philemon, wherever he was, along with this epistle: thou therefore receive him, that is, mine own bowels; meaning his son, who, in a spiritual sense, came out of his bowels, to whom he stood in the relation of a spiritual father; so the Syriac version renders it, as my son, so receive him; see...