Each and all of the saints in Philippi are greeted from the brothers who are with Paul, i.e., his colleagues and friends; and from the saints who are connected with Caesar's household. Where this is located depends on the city of origin (see introduction).
Paul's closing benediction (v. 23) sounds a central note in his theology and experience: the grace of the Lord Jesus Christ. This is the Gospel in a nutshell! The phrase your spirit (pneuma) is used frequently in the NT to mean the whole person and simply means “with you.”
Beare, F. W. A Commentary on the Epistle to the Philippians. BNTC. 3d ed. London: Adam and Charles Black, 1973.
Beet, J. A. A Commentary on St. Paul's Epistles to the Ephesians, Philippians, Colossians, and to Philemon. Salem, Ohio: Schmul, n.d.
Hawthorne, G. F. Philippians. WBC. Vol. 43. Waco, Tex.: Word, 1983.
Lightfoot, J. B. St. Paul's Epistle to the Philippians. London: Macmillan, 1913. Reprint: Zondervan, 1956.
Martin, R. P. Philippians. NCBC. London: Marshall, Morgan & Scott, 1976.
Wesley, John. Explanatory Notes Upon the New Testament. London: Epworth, 1941.