John the Apostle
Revelation 14:18ESV·traditional attribution

And another angel came out from the altar, the angel who has authority over the fire, and he called with a loud voice to the one who had the sharp sickle, “Put in your sickle and gather the clusters from the vine of the earth, for its grapes are 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 from the altar,.... Where are the souls of the martyrs of Jesus, Rev 6:9 and whom this angel is thought by some to represent, in his address to him that had the sharp sickle, crying for vengeance on the wicked of the earth, who had shed their blood: the allusion seems to be to the altar of burnt offerings, where...

Albert Barnes Presbyterian @notesbybarnes

Verse 18. And another angel. The sixth in order. He came, like the angel in , with a command to him who had the sickle to go forth and execute his commission. Came out from the altar. This stood in the front of the temple, (; compare ,) and was the place where burnt-sacrifices were made.