Deuteronomy 12:32

But whatsoever I command you, that take heed ye do: and put nought thereto, nor take ought therefrom.

Deuteronomy 4:2

Ye shall put nothing unto the word which I command you, neither do ought therefrom, that ye may keep the commandments of the LORD your God which I command you.

Joshua 1:7

Above all things, be strong and harden thyself, to observe and to do according to all the laws which Moses my servant commanded thee. Turn there from neither to the righthand, nor to the left: that thou mayest have understanding in all thou takest in hand.

Proverbs 30:6

Put thou nothing therefore unto his words, lest he reprove thee, and thou be found as a liar.

Revelation 22:18-19

I testify unto every man that heareth the words of 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.

Deuteronomy 13:18

when thou hast hearkened unto the voice of the LORD thy God, to keep all his commandments which I command thee this day so that thou do that which is right in the eyes of the LORD thy God.

Matthew 28:20

teaching them to observe all things, whatsoever I commanded you. And lo, I am with you always even until the end of the world."

Treasury of Scripture Knowledge

Summary

What thing soever I command you, observe to do it: thou shalt not add thereto, nor diminish from it.

Bible References

Thou shalt not

Deuteronomy 4:2
Ye shall put nothing unto the word which I command you, neither do ought therefrom, that ye may keep the commandments of the LORD your God which I command you.
Deuteronomy 13:18
when thou hast hearkened unto the voice of the LORD thy God, to keep all his commandments which I command thee this day so that thou do that which is right in the eyes of the LORD thy God.
Joshua 1:7
Above all things, be strong and harden thyself, to observe and to do according to all the laws which Moses my servant commanded thee. Turn there from neither to the righthand, nor to the left: that thou mayest have understanding in all thou takest in hand.
Proverbs 30:6
Put thou nothing therefore unto his words, lest he reprove thee, and thou be found as a liar.
Matthew 28:20
teaching them to observe all things, whatsoever I commanded you. And lo, I am with you always even until the end of the world."
Revelation 22:18
I testify unto every man that heareth the words of 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.

General references

Genesis 6:22
And Noah did according to all that God commanded him.
Genesis 21:4
and Abraham circumcised Isaac his son when he was eight days old, as God commanded him.
Leviticus 8:4
And Moses did as the LORD commanded him, and the people gathered themselves together unto the door of the tabernacle of witness.
Numbers 1:54
And the children of Israel did according to all that the LORD commanded Moses.
Deuteronomy 1:18
And I commanded you the same season, all the things which ye should do.
Deuteronomy 4:2
Ye shall put nothing unto the word which I command you, neither do ought therefrom, that ye may keep the commandments of the LORD your God which I command you.
Deuteronomy 11:32
Take heed, therefore, that ye do all the commandments and laws, which I set before you this day.
Psalm 119:4
Thou hast given straight charge to keep thy commandments: