This greeting is in my own hand—Paul.
The apostle closes his epistle, I. With salutations to the church of Corinth, first from those of Asia, from Priscilla and Aquila (who seem to have been at this time inhabitants of Ephesus, vid. Act 18:26), with the church in their house (Co1 16:19), and from all the brethren (Co1 16:20) at Ephesus, where, it is highly probable at least, he then was.
Commenting on 1 Corinthians 16:19-24
Verse 21. The salutation of me Paul with mine own hand. It is evident that Paul was accustomed to employ an amanuensis in penning his epistles, though he signed his own name, and expressed his Christian salutation in every epistle, . This gave a sanction to what was written; was a proof that it was his own, and was a valuable token of affectionate regard.
salutation . . . with mine own hand--He therefore dictated all the rest of the Epistle.