John the Apostle
Revelation 14:15ESV·traditional attribution

And another angel came out of the temple, calling with a loud voice to him who sat on the cloud, “Put in your sickle, and reap, for the hour to reap has come, for the harvest of the earth is fully ripe.”

Matthew Henry Presbyterian @wholebiblehenry

Here we have the vision of the harvest and vintage, introduced with a solemn preface. Observe, I. The preface, Rev 14:13. Here note, 1. Whence this prophecy about the harvest came: it came down from heaven, and not from men, and therefore it is of certain truth and great authority. 2.

Commenting on Revelation 14:13-20

John Gill Reformed Baptist @doctorgill

And another angel came out of the temple,.... Not the Holy Spirit, who, being God omniscient, knows the day and hour of judgment, which is a secret to men and angels, as Napier thinks; since though he dwells in the church as his temple, yet is never called an angel; nor does this angel represent the souls under the altar, who come out from thence...

Albert Barnes Presbyterian @notesbybarnes

Verse 15. And another angel. The fourth in order, . Came out of the temple. . Came, as it were, from the immediate presence of God; for the temple was regarded as his peculiar dwelling-place. Crying with a loud voice to him that sat on the cloud. To the Messiah, .