Filemon 1:13

1:13 I wanted to keep him so that he could serve me in your place ¹  during ²  my imprisonment for the sake of the gospel. ³ 

Filemon 1:15

1:15 For perhaps it was for this reason that he was separated from you for a little while, so that you would have him back eternally, ⁴ 

[1:13]  ¹ tn This is one of the clearest texts in the NT in which ὑπέρ is used for substitution. Cf. ExSyn 387.

[1:13]  ² tn Grk “in my imprisonment.” Paul seems to expect release from his imprisonment after some time (cf. v. 22), but in the meantime the assistance that Onesimus could provide would be valuable to the apostle.

[1:13]  ³ tn Grk “in the chains of the gospel.” On the translation “imprisonment for the sake of the gospel,” cf. BDAG 219 s.v. δεσμός 1.a where it says: “Oft. simply in ref. to the locale where bonds or fetters are worn imprisonment, prison (Diod. S. 14, 103, 3; Lucian, Tox. 29; Jos., Ant. 13, 294; 302, Vi. 241; Just., A I, 67, 6 al.) Phil 1:7, 13f, 17; Col 4:18; Phlm 10. μέχρι δεσμῶν 2 Ti 2:9. ἐν τοῖς δ. τοῦ εὐαγγελίου in imprisonment for the gospel Phlm 13; cf. ISm 11:1; Pol 1:1.”

[1:15]  ⁴ sn So that you would have him back eternally. The notion here is not that Onesimus was to be the slave of Philemon eternally, but that their new relationship as brothers in Christ would transcend the societal structures of this age. The occasion of Onesimus’ flight to Rome would ultimately be a catalyst in the formation of a new and stronger bond between these two men.