Albert Barnes Commentary Philippians 1:26

"that your glorying may abound in Christ Jesus in me through my presence with you again." — Philippians 1:26 (ASV)

That your rejoicing may be more abundant in Christ Jesus. Through the mercy and grace of Christ. If he was spared, his deliverance would be traced to Christ, and they would rejoice together in one who had so mercifully delivered him.

For me by my coming to you again. Their joy would not only be that he was delivered, but that he was permitted to see them again.