What is the meaning of Revelation 22:18?

* The two F.O.G. Bibles & Commentary below are currently a work in progress.

I testify to everyone who hears the words of prophecy in this book: If anyone adds to them, God will add to him the plagues described in this book.

Berean Standard Bible (BSB)

I testify to everyone who hears the words of the prophecy of this book, if anyone adds to them, may God add to him the plagues which are written in this book.

World English Bible (WEB)

For{G1063} I testify{G4828}{(G5736)} unto every man{G3956} that heareth{G191}{(G5723)} the words{G3056} of the prophecy{G4394} of this{G5127} book{G975}, If{G1437} any man{G5100} shall add{G2007}{(G5725)} unto{G4314} these things{G5023}, God{G2316} shall add{G2007}{(G5692)} unto{G1909} him{G846} the plagues{G4127} that are written{G1125}{(G5772)} in{G1722} this{G5129} book{G975}:

Strong's King James

(18) I testify, everyone hearing the prophetic message of this scroll, if anyone lays upon it, אֱלֹהִים Elohim lays upon him, the plagues written in this scroll.

The F.O.G*

[18] I solemnly warn everyone who hears the prophetic words of this book: If anyone adds to them, God will add to them the plagues described in this book.

The F.O.G Paraphrase

‘For I testify to every one hearing the words of the prophecy of this scroll, if any one may add unto these, God shall add to him the plagues that have been written in this scroll,

Young's Literal Translation