Charles Ellicott Commentary Revelation 22:18-19

"I testify unto every man that heareth the words of the prophecy of this book, if any man shall add unto them, God shall add unto him the plagues which are written in this book: and if any man shall take away from the words of the book of this prophecy, God shall take away his part from the tree of life, and out of the holy city, which are written in this book." — Revelation 22:18-19 (ASV)

I testify to every man that hears.—Omit “For,” and read, I testify to everyone that hears... The “I” is emphatic; it introduces the final warning. The revelation must not be tampered with. If anyone shall have added to them, God shall add to him the plagues which are written in this book; and if anyone shall have taken away from the words of the book of this prophecy, God shall take away his portion from the tree of life, and out of the holy city which are written (or printed) in this book. We may compare this to Deuteronomy 4:2 and Deuteronomy 12:32.

The words are a solemn protest against the spirit that handles God's word rashly or deceitfully; that adds its own thoughts, or makes its own desires the parent of its interpretations; that dilutes the force of its warnings, or diminishes the fullness of its promises. The right of continual access to the tree of life was the promise of Revelation 22:14; this right or freedom is forfeited by those who deal falsely or faithlessly with Christ's words here.

To a lesser degree, it is true that those who leave this book unstudied and unprayed over lose much spiritual sustenance and comfort. How much more do those lose who trifle with it, ignore its spiritual teachings, and sin against the laws of that kingdom whose progress it so vividly portrays.