Deuteronomy 4:2
1 Now, Israel, pay attention to the statutes and ordinances I am about to teach you, so that you might live and go on to enter and take possession of the land that the Lord, the God of your ancestors, is giving you. 2 Do not add a thing to what I command you nor subtract from it, so that you may keep the commandments of the Lord your God that I am delivering to you. 3 You have witnessed what the Lord did at Baal Peor, how he eradicated from your midst everyone who followed Baal Peor. 4 But you who remained faithful to the Lord your God are still alive to this very day, every one of you.
Revelation 22:18
16 “I, Jesus, have sent my angel to testify to you about these things for the churches. I am the root and the descendant of David, the bright morning star!” 17 And the Spirit and the bride say, “Come!” And let the one who hears say: “Come!” And let the one who is thirsty come; let the one who wants it take the water of life free of charge. 18 I testify to everyone who hears the words of the prophecy contained in this book: If anyone adds to them, God will add to him the plagues described in this book. 19 And if anyone takes away from the words of this book of prophecy, God will take away his share in the tree of life and in the holy city that are described in this book. 20 The one who testifies to these things says, “Yes, I am coming soon!” Amen! Come, Lord Jesus!
Notes and References
"... Deuteronomy 4:2 warns Israel “you must not add anything to what I command you or take anything away from it,” which can be compared to the very end of the Bible at Revelation 22:18 where we hear similarly that whoever adds to or subtracts from the words of prophecy in Revelation, that God will add to him the plagues mentioned in the book. The tone of this warning indicates the seriousness of the matter, and it also indicates the prophetic authority John believes his words carry. They come from God, just as much as the direct speech in Deuteronomy 4:2 ..."
Witherington, Ben Torah Old and New: Exegesis, Intertextuality, and Hermeneutics (p. 331) Fortress Press, 2018