thou shalt not

Deuteronomy 4:2
You must not add to or subtract from what I command you, so that you may keep the commandments of the LORD your God I am giving you.

Deuteronomy 13:18
because you obey the LORD your God, keeping all His commandments I am giving you today, doing what is right in the eyes of the LORD your God.

Joshua 1:7
Above all, be strong and very courageous. Be careful to observe all the law My servant Moses commanded you. Do not turn from it to the right or to the left, so that you may prosper wherever you go.

Proverbs 30:6
Do not add to His words, lest He rebuke you and prove you a liar.

Matthew 28:20
and teaching them to obey all that I have commanded you. And surely I am with you always, to the very end of the age."

Revelation 22:18, 19
I testify to everyone who hears the words of prophecy in this book: If anyone adds to them, God will add to him the plagues described in this book. . . .