What does Philemon 1:19 mean?

This verse extends Paul's focus on Onesimus' freedom which began in verse 8, and shifted to a personal emphasis in verse 17. It is clear Paul was personally marking these words on paper, adding to the authenticity of his promise. Paul often used others to physically write down the words of his letters, a common practice in the first century. This is the same idea as a modern stenographer, or transcriber.

In this letter, Timothy may have been Paul's assistant (Philemon 1:1), as was also likely the case in 2 Corinthians, Philippians, Colossians, 1 Thessalonians, and 2 Thessalonians. However, Paul often hand-wrote his own personal comments (1 Corinthians 16:21; Galatians 6:11; Colossians 4:18; 2 Thessalonians 3:17).

In contrast with Paul's commitment to repay debt for Onesimus, he mentions that Philemon is deeply indebted to Paul in the first place. In other words, Paul believed he had been involved in a particularly powerful blessing on Philemon's life. This was probably not financial, since Philemon appears to have been quite wealthy, and Paul was the missionary needing support. Paul likely had in mind the fact that his missionary work in the region where Philemon lived led to his conversion, a vital spiritual blessing.