John the Apostle
Revelation 3:18BSB·traditional attribution

I counsel you to buy from Me gold refined by fire so that you may become rich, white garments so that you may be clothed and your shameful nakedness not exposed, and salve to anoint your eyes so that you may see.

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

John Gill Reformed Baptist @doctorgill

Behold, I stand at the door and knock,.... The phrase of standing at the door may be expressive of the near approach, or sudden coming of Christ to judgment, see Jam 5:9; and his knocking may signify the notice that will be given of it, by some of the immediate forerunners and signs of his coming; which yet will be observed but by a few...

Albert Barnes Presbyterian @notesbybarnes

Verse 18. I counsel thee to buy of me gold tried in the fire. Pure gold; such as has been subjected to the action of heat to purify it from dross. . Gold here is emblematic of religion--as being the most precious of the metals, and the most valued by men.