The Apostle Paul
Galatians 1:1ESV·traditional attribution

Paul, an apostle—not from men nor through man, but through Jesus Christ and God the Father, who raised him from the dead—

John Calvin Reformed @genevareformer

1. Paul, an apostle. In the salutations with which he commenced his Epistles, Paul was accustomed to claim the title of “an Apostle.” His object in doing so, as we have remarked on former occasions, was to employ the authority of his station, for the purpose of enforcing his doctrine.

Matthew Henry Presbyterian @wholebiblehenry

In these verses we have the preface or introduction to the epistle, where observe, I. The person or persons from whom this epistle is sent - from Paul an apostle, etc., and all the brethren that were with him. 1. The epistle is sent from Paul; he only was the penman of it.

Commenting on Galatians 1:1-5

John Gill Reformed Baptist @doctorgill

Paul an apostle, not of men, neither by man,.... The writer of this epistle, Paul, puts his name to it, as to all his epistles, excepting that to the Hebrews, if that be his, being neither afraid nor ashamed to own what is herein contained.