exactly. ^^^^ this.

Deuteronomy 4:2

2 You shall not add to the word which I am commanding you, nor take away from it, that you may keep the commandments of the Lord your God which I command you.

Deuteronomy 12:32

32 “[a]Whatever I command you, you shall be careful to do; you shall not add to nor take away from it.

Revelation 22:18

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