Philemon 1:1

I. In the first two verses of the preface we have the persons from and to whom it is written, with some annexed note or title, implying somewhat of argument to the purpose of the letter. 1. The persons writing: Paul, the principal, who calls himself a prisoner of Jesus Christ, that is, for Jesus Christ. To be a prisoner simply is no comfort nor honour; but such as Paul was, for the faith and preaching of the gospel, this was true glory, and proper to move Philemon upon the request made to him by such a one. A petition from one suffering for Christ and his gospel would surely be tenderly regarded by a believer and minister of Christ, especially when strengthened too with the concurrence of Timothy, one eminent in the church, sometimes called by Paul his son in the faith, but now, it is likely, grown more in years, he styles him his brother. What could be denied to two such petitioners? Paul is not slight in serving a poor convert; he gets all the additional help he can in it. 2. The persons written to are Philemon and Apphia, and with them Archippus, and the church in Philemon's house. Philemon, the master of Onesimus, was the principal, to whom the letter is inscribed, the head of the family, in whom were the authority and power of taking in or shutting out, and whose property Onesimus was: with him therefore chiefly lay the business.

— Matthew Henry's Concise Commentary (public domain)