The strongest illness, so natural in a master, required the strongest medicine. It is offered here.
The Apostle’s words placed Philemon under necessity to receive Onesimus. There was no possibility of evasion.
Chrysostom says: “Nothing so persuades one to fulfill a request as not asking everything at once.
Therefore see after what praises and after what preparation the Apostle expressed this great request.
He called Onesimus his son, a participant in the Gospel, his own heart. He said, ‘You are gaining a brother in him; receive him as a brother.’
Only then does he add, ‘as myself.’ Paul was not ashamed to say this.
If he was not ashamed to be called the slave of the faithful, and even acknowledged himself to be such, still less could he shrink from this.
The meaning of his words is this: if you are of one mind with me, if you strive toward the same thing as I do, if you count me a friend, then receive him as myself.”
Blessed Theodoret continues this discourse: “What is more persuasive, what is firmer than these words?
If, says the Apostle, you deem communion with me worthy of any respect, then receive as myself the one who has admitted this extraordinary change in himself, from slave to brother.”
Ambrosiaster concludes it thus: “The Apostle shows that he has so strong an affection for Onesimus that he agrees to have Philemon himself as his partner only on this condition.
He must receive Onesimus as the Apostle himself. Such a word had to bring fear upon Philemon.
For this reason at least he would receive him, if love could not incline him to do so.”