J. B. Lightfoot on Philemon 1:17-20

τῇ ἐμῇ χειρί, ἐγὼ ἀποτίσω· ἵνα μὴ λέγω σοι, ὅτι καὶ σεαυτόν μοι προσοφέιλεις. ^{20}ναί, ἀδελφέ, ἐγώ σου ὀναίμην ἐν Κυρίῳ· ἀνάπαυσόν μου τὰ σπλάγχνα ἐν Χριστῷ. ἵνα μὴ λέγω] ‘_not to say_’, as 2 Cor. ix. 4. There is a suppressed thought, ‘though indeed you cannot fairly claim repayment’, ‘though indeed you owe me (ὀφείλεις) as much as this’, on which the ἵνα μὴ κ.τ.λ. is dependent. Hence προσοφέιλεις ‘_owest besides_’; for this is the common meaning of the word. σεαυτόν] St Paul was his spiritual father, who had begotten him in the faith, and to whom therefore he owed his being; comp. Plato _Legg._ iv. p. 717 B ὡς θέμις ὀφέιλοντα ἀποτίνειν τὰ πρῶτά τε καὶ μέγιστα ὀφειλήματα ... νομίζειν δὲ, ἃ κέκτῃται καὶ ἔχει, _πάντα εἶναι τῶν γεννησάντων_ ... ἀρχόμενον ἀπὸ τῆς οὐσίας, δεύτερα τὰ τοῦ σώματος, τρίτα τὰ τῆς ψυχῆς, _ἀποτίνοντα δανείσματα_ κ.τ.λ. 20. ναί] introducing an affectionate appeal as in Phil. iv. 3 ναὶ ἐρωτῶ καὶ σέ. ἀδελφέ] It is the entreaty of a brother to a brother on behalf of a brother (ver. 16). For the pathetic appeal involved in the word see the notes on Gal. iii. 15, vi. 1, 18; and comp. ver. 7. ἐγώ] ‘I seem to be entreating for Onesimus; but I am pleading for _myself_: the favour will be done to me’; comp. ver. 17 προσλαβοῦ αὐτὸν ὡς ἐμέ. The emphatic ἐγώ identifies the cause of Onesimus with his own. σου ὀναίμην] ‘_may I have satisfaction, find comfort in thee_’, i.e. ‘may I receive such a return from thee, as a father has a right to expect from his child.’ The common use of the word ὀναίμην would suggest the thought of filial offices; e.g. Arist. _Thesm._ 469 οὕτως ὀναίμην τῶν _τέκνων_, Lucian _Philops._ 27 πρὸς τὴν ὄψιν τῶν _υἱέων_, οὕτως ὀναίμην, ἔφη, τούτων, Ps-Ignat. _Hero_ 6 ὀναίμην σου, _παιδίον_ ποθεινόν, Synes. _Ep._ 44 οὕτω τῆς ἱερᾶς φιλοσοφίας ὀναίμην καὶ προσέτι τῶν _παιδίων_ τῶν ἐμαυτοῦ, with other passages quoted in Wetstein. So too for ὄνασθαι, ὄνησις, compare Eur. _Med._ 1025 sq. πρὶν σφῷν _ὄνασθαι_ ... ἄλλως ἄρ’ ὑμᾶς, ὦ _τέκν’_, ἐξεθρεψάμην, _Alc._ 333 ἅλις δὲ _παίδων_· τῶν δ’ _ὄνησιν_ )εύχομαι θεοῖς γενέσθαι, Philem. _Inc._ 64 (IV. p. 55 Meineke) ἔτεκές με, μῆτερ, καὶ γένοιτό σοι _τέκνων ὄνησις_, ὥσπερ καὶ δίκαίον ἐστί σοι, Ecclus. xxx. 2 ὁ παιδεύων τὸν _ὑὶον_ αὐτοῦ _ὀνήσεται_ ἐπ’ αὐτῷ (the only passage in the LXX where the word occurs). The prayer ὀναίμην σου, ὀναίμην ὑμῶν, etc., occurs several times in Ignatius; _Polyc._ 1, 6, _Magn._ 2, 12, _Ephes._ 2. It is not unlikely that ὀναίμην here involves a reference to the name Onesimus; see the note on ver. 11. The Hebrew fondness for playing on names makes such an allusion at least possible.