I, Paul, write this with my own hand, I will repay it—to say nothing of your owing me even your own self.
ἐγὼ Παῦλος ἔγραψα τῇ ἐμῇ χειρί, ἐγὼ ἀποτίσω· ἵνα μὴ λέγω σοι ὅτι καὶ σεαυτόν μοι προσοφείλεις.
I Paul write it with my 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 my 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 you how you owe unto me even your 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 you how you owe to me even your own self besides. Not only your own things, but yourself 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.
[For moral, see Phm 1:25]
Haydock Catholic Bible Commentary: Philemon
I, Paul, have written, and testified this with my own hand. Some think he wrote the whole letter, with his own hand, to make it more acceptable to Philemon. — Not to say to thee, that thou owest me thy own self, the eternal salvation of thy soul, by thy conversion to the faith of Christ. Wi.