"The letter now concludes with a series of standard (for Paul) greetings (vv. 19-22) and the grace-benediction (v. 23). But Paul cannot quite give up the urgency of the letter, so he interrupts these two rather constant elements of his conclusions with one final word of warning to those who have been causing him grief, this time in the form of an extraordinary curse formula (v. 22). The apparent harshness of this warning is matched by the equally unusual addition of a final word of affirmation of his love for them (v. 24), found only here in his extant letters. Thus even to the end the unique concerns that have forged this letter find their expression."410
16:19 Several churches in the Roman province of Asia had come into existence while Paul used its capital city, Ephesus, as his base of operations (Acts 19:10).
The names of Aquila and Prisca (Priscilla) usually occur in reverse order in the New Testament. Evidently their friends, of which Paul was one, felt free to use both orders. This suggests that they served the Lord as a harmonious team with individual strengths and talents. They had lived in Corinth after leaving Rome (Acts 18:2), and it was there that Paul first met them. They had left Corinth for Ephesus with Paul and settled in that city (Acts 18:18-21). Their house became a meeting place for the church (cf. Rom. 16:5). Church buildings were unknown until the third century.411
16:20 The holy kiss, holy because saints (1:2) exchanged it, was a common practice among believers, and it still is today in some parts of the world. It consisted of women kissing women and men kissing men on the cheek.
16:21 Paul customarily dictated his letters, and a secretary wrote them down (cf. Rom. 16:22). However, he usually added a word of greeting at the end in his own hand that authenticated his epistles as coming from him (cf. Gal. 6:11; Col. 4:18; 2 Thess. 3:17). All of what follows is probably what he added.
16:22 Normally Paul used the Greek word agapefor love (except in Titus 3:15). Here he used phileo. Consequently this may have been a saying believers used in the congregational worship of the churches. "Maranatha"(NASB) is an Aramaic expression meaning "Our Lord, come."Probably Paul did not translate it into Greek because believers commonly spoke it in Aramaic in the services of the early church (cf. Rev. 22:20). Since it was Aramaic it probably originated in Palestine where people spoke that language. They exported it to the Greek-speaking congregations that retained its form.
"It is strange to meet with an Aramaic phrase in a Greek letter to a Greek Church. The explanation is that that phrase had become a watchword and a password. It summed up the vital hope of the early Church, and Christians whispered it to each other, identified each other by it, in a language which the heathen could not understand."412
"It would appear, then, that the fixed usage of the term Maranatha' by the early Christians was a witness to their strong belief in the imminent return of Christ. If they knew that Christ could not return at any moment because of other events or a time period that had to transpire first [i.e., the Tribulation], why did they petition Him in a way that implied that He could come at any moment?"413
16:23-24 Paul concluded this strong but loving epistle with a prayerful benediction of God's grace. Note that this letter also began, "Grace to you"(1:3).
"Grace is the beginning and the end of the Chrstian [sic] gospel; it is the single word that most fully expresses what God has done and will do for his people in Christ Jesus."414
Paul also added assurance of his own love for all the believers in Corinth, not just those who supported him.
(NT only) to listen to the NET Bible 
