The second demand Paul makes of Philemon is ironical. On the one hand, the reader supposes that Paul is offering to make good whatever financial or business loss Philemon has suffered as a result of Onesimus's failure (whatever that might be). While Paul owes Philemon nothing, even as Christ owes us nothing, he involves himself in Onesimus's affairs in order to pay his debt, whether financial or interpersonal, even as Christ (who knew no sin) took upon himself the sins of us all (so Rom 5:6-11). Paul's involvement has a firm christological basis.
Yet behind Paul's offer is the common awareness that he is Philemon's spiritual patron—that Philemon is obliged to Paul even as Onesimus is. At day's end, then, Paul's offer to pay Onesimus's costs—if he has done you any wrong or owes you anything—is canceled by Philemon's own debt—you owe me your very self. The force of Paul's words is neither coercive or paternalistic but firmly persuasive. Even the rhetorician's trick of mentioning the unmentionable (not to mention that you owe me; compare v. 8) does not seem heavy-handed (see Wright 1986:188). It rather calls attention to what is true about Paul's relationship with both Philemon and Onesimus and perhaps explains, therefore, why he requests a change in Onesimus's status but then offers to pay all his debts: the spiritual reality (what Philemon owes Paul) naturally yields a social result (what Paul requests of and offers to Philemon).
Harris says that the final reference to Philemon's debt to Paul in verse 19 qualifies Paul's offer to pay off any monetary debts; however, there are no legal debts in view (see introduction). Paul's concern is reconciliation, not the settling of debts (Harris 1991:274); and reconciliation will have its result in Onesimus's freedom.
Further implicit in Paul's offer is that Onesimus himself has satisfied Philemon's obligation to Paul (and therefore paid his debt in full) by taking care of Paul's needs while in prison (see commentary on v. 13). Behind the prospect of Paul's exchange, then, is the satisfaction of Onesimus's. What Paul offers to do as an agent of God's reconciling grace has already been done by Onesimus! There is a sense, then, that Onesimus has already proved himself as Philemon's brother and partner; it is left then to Philemon to acknowledge his debt to Onesimus by treating him as his brother and partner as well.
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