Deuteronomy 4:2 in the World English Bible
You shall not add to the word which I command you, neither shall you take away from it, that you may keep the commandments of the LORD your God which I command you.
Context
1 Now therefore hearken, O Israel, unto the statutes and unto the judgments, which I teach you, for to do them, that ye may live, and go in and possess the land which the LORD God of your fathers giveth you.
2 Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the LORD your God which I command you.
3 Your eyes have seen what the LORD did because of Baal-peor: for all the men that followed Baal-peor, the LORD thy God hath destroyed them from among you.