John the Apostle
Revelation 14:15BSB·traditional attribution

Then another angel came out of the temple, crying out in a loud voice to the One seated on the cloud, “Swing Your sickle and reap, because the time has come to harvest, for the crop of the earth is 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, .