John the Apostle
Revelation 3:10BSB·traditional attribution

Because you have kept My command to persevere, I will also keep you from the hour of testing that is about to come upon the whole world, to test those who dwell on the earth.

Matthew Henry Presbyterian @wholebiblehenry

We have now come to the sixth letter, sent to one of the Asian churches, where observe, I. The inscription, showing, 1. For whom it was more immediately designed: The angel of the church of Philadelphia; this also was a city in Asia Minor, seated upon the borders of Mysia and Lydia, and had its name from that brotherly love for which it was eminent.

Commenting on Revelation 3:7-13

John Gill Reformed Baptist @doctorgill

Behold, I come quickly,.... To bring on this hour of temptation on the reformed churches, which will be at the beginning of this period; to help and deliver, save and preserve the truly godly among them; to destroy antichrist, and introduce the latter day glory: hold that fast which thou hast; either her grace in the exercise of it, as her faith, patience, &c.

Albert Barnes Presbyterian @notesbybarnes

Verse 10. Because thou hast kept the word of my patience. My word commanding or enjoining patience; that is, thou hast manifested the patience which I require. They had shown this in the trials which they had experienced; he promises now, that in return he will keep them in the future trials that shall come upon the world.