What does Philippians 2:23 mean?

Timothy was still with Paul when Philippians was written, but Paul hoped to send him to Philippi soon. He seems to be waiting for more information on his current legal situation. Paul had spent two years under house arrest (Acts 28:30). This shows the letter was written approximately AD 62, giving one of the most accurate dates of any of Paul's letters. Paul probably wanted to wait to send Timothy until he had confirmation about his impending release.

Timothy would later serve as leader of the church in Ephesus (1 and 2 Timothy). During Paul's second imprisonment, sometime between AD 64 and 68, Paul wrote 2 Timothy to urge Timothy to visit him before winter (perhaps written in the fall of 65 to 67). Timothy would outlive his mentor, serving as a church leader until his own death, traditionally dated around AD 97, martyred for attempting to stop a procession honoring the goddess Diana.