Revelation 22:18

22:18 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

Other Translation

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:
-King James Version