John the Apostle
Revelation 3:21ESV·traditional attribution

The one who conquers, I will grant him to sit with me on my throne, as I also conquered and sat down with my Father on his throne.

Matthew Henry Presbyterian @wholebiblehenry

We now come to the last and worst of all the seven Asian churches, the reverse of the church of Philadelphia; for, as there was nothing reproved in that, here is nothing commended in this, and yet this was one of the seven golden candlesticks, for a corrupt church may still be a church. Here we have, as before, I. The inscription, to whom, and from whom. 1.

Commenting on Revelation 3:14-22

Albert Barnes Presbyterian @notesbybarnes

Verse 21. To him that overcometh. . Will I grant to sit with me in my throne. That is, they will share his honours and his triumphs. ; . Even as I also overcame. As I gained a victory over the world, and over the power of the tempter.

Jamieson-Fausset-Brown Reformed @jfbcommentary

sit with me in my throne-- (Rev 2:26-27; Rev 20:6; Mat 19:28; Mat 20:23; Joh 17:22, Joh 17:24; Ti2 2:12). The same whom Christ had just before threatened to spue out of His mouth, is now offered a seat with Him on His throne! "The highest place is within reach of the lowest; the faintest spark of grace may be fanned into the mightiest flame of love" [TRENCH].