John the Apostle
Revelation 10:5ESV·traditional attribution

And the angel whom I saw standing on the sea and on the land raised his right hand to heaven

Matthew Henry Presbyterian @wholebiblehenry

Here we have an account of another vision the apostle was favoured with, between the sounding of the sixth trumpet and that of the seventh. And we observe, I. The person who was principally concerned in communicating this discovery to John - an angel from heaven, another mighty angel, who is so set forth as would induce one to think it could be no other...

Commenting on Revelation 10:1-7

John Gill Reformed Baptist @doctorgill

And the angel which I saw stand upon the sea and upon the earth,.... His right foot being on the one, and his left foot upon the other, as described in Rev 10:2; lifted up his hand to heaven; the Oriental versions read, "his right hand"; and so some copies, and the Complutensian edition: the man clothed in linen, Dan 12:6, who is the same...

Albert Barnes Presbyterian @notesbybarnes

Verse 5. And the angel which I saw stand, etc. . That is, John saw him standing in this posture when he made the oath which he proceeds to record. Lifted up his hand to heaven. The usual attitude in taking an oath, as if one called heaven to witness. See . Compare Barnes on "Da 12:7".