Paul now removes the excuse for anger, just in case it turned out that he had been so hurt by Onesimus that he would find it impossible to forgive him.
"If he hath wronged thee at all." See where and when he has introduced the mention of the injury; last, after having said so many things in his behalf. For since the loss of money is particularly apt to annoy men, that he might not accuse him of this, (for it was most likely that it was spent,) then he brings in this, and says, "If he hath wronged thee." He does not say, If he has stolen anything; but what? "If he hath wronged thee." At the same time he both confessed the offense, and not as if it were the offense of a servant, but of a friend against a friend, making use of the expression of "wrong" rather than of theft.
"Put that to mine account," he says, that is, reckon the debt to me, "I will repay it." Then also with that spiritual pleasantry, "I Paul write it with mine own hand." At once movingly and pleasantly; if when Paul did not refuse to execute a bond for him, he should refuse to receive him! This would both shame Philemon into compliance, and bring Onesimus out of trouble. "I write it," he says, "with mine own hand." Nothing is more affectionate than these "bowels," nothing more earnest, nothing more zealous. See what great concern he bestows in behalf of one man. "Albeit I do not say to thee how thou owest unto me even thine own self besides." Then that it might not appear insulting to him, whom he requests, if he had not the confidence to ask and obtain in behalf of a theft, he in some measure relieves this, saying, "That I say not unto thee how thou owest to me even thine own self besides." Not only thine own things, but thyself also. And this proceeded from love, and was according to the rule of friendship, and was a proof of his great confidence. See how he everywhere provides for both, that he may ask with great security, and that this may not seem a sign of too little confidence in him.
But if anyone has wronged you, or owes you anything, charge that to me. As an imitator of his master, and having Christ speaking in him, he ought to do the things which Christ did according to his ability. For if he bore our weaknesses and suffered our wounds, the Apostle rightly opposes himself on behalf of Onesimus and promises what he owed. But as we have said above, all that which was taken away by theft and lost through luxury could not be made right, which Philemon valued greatly while he received his runaway slave, lost money and eternal brother, thus making himself a debtor to the Apostle through him.
"And if he has wronged you". Paul did not say, "He stole," but the verb is cut short. He says he "wronged" "or owes".
"charge that to me". For it was likely that they themselves had consumed together the things that had been stolen, and Paul says, "charge this to me," that is, charge these things as a debt to me, let the obligation be held against me.
"I, Paul, write". He wrote with spiritual grace, as if he said, But for safe keeping, that I will repay the debt, I have made the letters with my own hand.
"to avoid saying to you that you owe me your own self as well". So that Paul may not seem to insult him by not daring to appeal to him openly on behalf of the runaway slave (for this would show Philemon to be somewhat harsh), it shows that Paul is also very confident in Philemon. For he says not only your own things, but also yourself you owe to me.
Second, he offers to make good any injury to Philemon, saying, And if he did you any injury or owes you anything, namely by leaving his service, charge it to me. As if to say, I will make satisfaction. Galatians 6.2.: ‘Bear one another’s burdens.’ And more, because he first offers to make it good; second, he shows that Philemon is in his debt, not of necessity but of will.
[AD 384] Ambrosiaster on Philemon 1:18