John the Apostle
Revelation 19:21ESV·traditional attribution

And the rest were slain by the sword that came from the mouth of him who was sitting on the horse, and all the birds were gorged with their flesh.

Matthew Henry Presbyterian @wholebiblehenry

No sooner was the marriage solemnized between Christ and his church by the conversion of the Jews than the glorious head and husband of the church is called out to a new expedition, which seems to be the great battle that was to be fought at Armageddon, foretold Rev 16:16. And here observe, I. The description of the great Commander, 1.

Commenting on Revelation 19:11-21

John Gill Reformed Baptist @doctorgill

And the remnant were slain,.... Not only the kings of the earth, and their armies, that will now be gathered together, but all the remains of Papists, Pagans, and Mahometans, in the several parts of the world, even all the enemies of Christ: these will be slain with the sword of him that sat upon the horse; upon the white horse, as the Ethiopic version...

Albert Barnes Presbyterian @notesbybarnes

Verse 21. And the remnant. The remainder of the assembled hosts--the army at large, in contradistinction from the leaders. Were slain with the sword. Cut down with the sword; not rescued for protracted torment. A proper distinction is thus made between the deceived multitudes and the leaders who had deceived them. Of him that sat upon the horse. The Messiah, . Which sword proceeded out of his mouth.