Did the Ten Commandments Exist Before Moses?

In the Reformed Faith, we hold that the Ten Commandments are but the summary of the whole Moral Law written on the heart of mankind in creation (Rom. 2:14-15). This is why we find so many instances of men operating out of an awareness of these commandments before they were given to Moses on Mt. Sinai.

* In Genesis 35, Jacob commanded the members of his household to put away their foreign gods, showing his awareness of the first and second commandments: Thou shalt have no other gods before me, and Thou shalt not make unto thee any graven image.

* In Job 1, Job offered sacrifices for his children in case they happened to curse God in their feasting and drinking, showing his awareness of the third commandment: Thou shalt not take the name of the Lord thy God in vain.

* In Exodus 16, the LORD chided the people in the wilderness for working on the seventh day, showing their awareness of the fourth commandment: Thou shalt remember the sabbath day to keep it holy.

* In Genesis 28, Jacob obeyed his father's prohibition against taking a wife from among the Canaanites, showing his awareness of the fifth commandment: Honour thy father and thy mother.

* In Genesis 4, Cain expected to be executed for killing his brother Abel, showing an awareness of the sixth commandment: Thou shalt not kill.

* In Genesis 39, Joseph refused to sin against God by lying with Potiphar's wife, showing his awareness of the seventh commandment: Thou shalt not commit adultery.

* In Genesis 20, Abimelech pleaded his innocence for taking another man's wife, showing his awareness of the eighth, and tenth commandments: Thou shalt not steal, and Thou shalt not covet thy neighbor's wife.

* In Genesis 12, Pharaoh rebuked Abraham for lying about his relationship with Sarah, showing his awareness of the ninth commandment: Thou shalt not bear false witness.