Appeal on Behalf of Onesimus
Onesimus, a slave, had runaway from his master, Philemon. Paul requested that Philemon show mercy to Onesumus. Paul appealed to Philemon to receive Onesimus as a brother in Christ and not to discipline him for his crime (as he had every right under the law to do). See "Laws Regarding Hebrew Servants - Exodus 21:1-11" and "Freeing Slaves - Deuteronomy 15:12-18" below.
8-21 Appeal on Behalf of Onesimus. In the main body of his letter, Paul appeals to Philemon to receive Onesimus back into his household, “no longer as a slave, but as a dear brother” (v16). Paul provides at least four reasons why Philemon should grant his request, two with reference to himself and two with reference to Philemon: First, Onesimus had become useful and dear to Paul (10-12). Second, whatever debts Onesimus may have created in relation to Philemon, Paul was willing to pay himself (18-19). Third, Paul honored Philemon’s right to decide how to deal with Onesimus’ debts (8-9, 14). However, fourth, Paul asked Philemon to address Onesimus’ debts to him in the light of his own debts to Paul (17, 19-20).