Revelation 22:18
“For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:”
I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star.
And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.
For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that 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 out of the book of life, and out of the holy city, and from the things which are written in this book.
He which testifieth these things saith, Surely I come quickly. Amen. Even so, come, Lord Jesus.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“What thing soever I command you, observe to do it: thou shalt not add thereto, nor diminish from it.”
“Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the Lord your God which I command you.”
“Add thou not unto his words, lest he reprove thee, and thou be found a liar.”
“Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the Lord your God which I command you.”
“What thing soever I command you, observe to do it: thou shalt not add thereto, nor diminish from it.”