John the Apostle
Revelation 4:1BSB·traditional attribution

After this I looked and saw a door standing open in heaven. And the voice I had previously heard speak to me like a trumpet was saying, “Come up here, and I will show you what must happen after these things.”

Matthew Henry Presbyterian @wholebiblehenry

We have here an account of a second vision with which the apostle John was favoured: After this, that is, not only "after I had seen the vision of Christ walking in the midst of the golden candlesticks," but "after I had taken his messages from his mouth, and written and sent them to the several churches, according to his command, after this I had...

Commenting on Revelation 4:1-7

John Gill Reformed Baptist @doctorgill

After this I looked,.... After John had seen the vision of Christ, in the midst of the golden candlesticks, with seven stars in his right hand; after he was bid to write what he had seen, and what were, and should be hereafter; and after he had by order written the seven epistles to the seven churches, he looked about him to see what else...

Albert Barnes Presbyterian @notesbybarnes

CHAPTER IV ANALYSIS OF THE CHAPTER THIS chapter properly commences the series of visions respecting future events, and introduces those remarkable symbolical descriptions which were designed to cheer the hearts of those to whom the book was first sent, in their trials, and the hearts of all believers in all ages, with the assurance of the final triumph of the gospel. See the Introduction.