A.T. Robertson Commentary Philemon 1:17

"If then thou countest me a partner, receive him as myself." — Philemon 1:17 (ASV)

If then thou countest me a partner (ε ουν με εχεις κοινωνον). As I assume that you do, condition of the first class.

Receive him as myself (προσλαβου αυτον ως εμε). "Take him to thyself (indirect second aorist middle of προσλαμβανω as in Ac 18:26) as myself." Surpassing delicacy and consummate tact. These words sound the death-knell of human slavery wherever the spirit of Christ is allowed to have its way. It has been a long and hard fight to break the shackles of human bondage even in Christian countries and there are still millions of slaves in pagan and Mohammedan lands. Paul wrote these words with wisdom and courage and sincerity.