Locate Sources for the 7 Commandments

4. Do Not Have Forbidden Sexual Relations
Five of the six types of relations that are forbidden by G-d to Gentiles are covered in Genesis 2:24: “Therefore a man shall leave his father and his mother and cling to his wife, and they shall become one flesh.” This verse explicitly forbids relations with one’s mother, with a woman who has ever been his father’s domestic partner or certified wife, with a woman who is currently a domestic partner or certified wife of another man, with another male, or with an animal. A Gentile is also forbidden to have relations with his maternal sister, which is learned from Gen. 20:13: “Moreover, she is indeed my sister, my father’s daughter, though not my mother’s daughter; and she became my wife.” (Note that Abraham said this to appease Abimelech. It was actually only figuratively true in his case, since Sarah was the daughter of Abraham’s brother. So they had the same paternal grandfather, who people often referred to as “father.”) It also was universally accepted that father-daughter relations would be included, as evidenced by the disgrace of Lot after he had relations with his two daughters, following G-d’s destruction of Sodom and Gomorrah (Gen. 19:29-36, and Rashi’s explanation of Gen. 20:1). Relations of a female with a female are likewise an abomination to G-d which is included as one of the subjects of the verse Lev. 18:3, which speaks against the immoral practices of the ancient Egyptians and Canaanites, and which Lev.18:30 refers to as “abominable traditions.” About these, the Midrash (Sifra) specifies: “A man would marry a man, a woman would marry a woman, and a woman would be married to two men.”

5. Do Not Commit Theft
The prohibition of theft is contained within the permission which G-d granted to Adam and Hava (Eve) in Genesis 2:16 to eat from the trees of the garden. This implies that if the permission had not been granted, they would have been forbidden to do so, because the property did not belong to them. This applied specifically to the fruit of the Tree of “Knowledge of Good and Evil” which was forbidden for them to take, under penalty of death (Genesis 2:17). This Noahide commandment was cited explicitly by Abraham in Genesis 21:25.

6. Don’t Eat Meat that was Taken from a Live Animal
Adam and Hava (Eve) were not given permission to kill animals for food, and this remained in effect until after the Flood. G-d permitted the eating of meat for the first time to Noah and his family after they left the Ark, which is why G-d at that time added the seventh commandment, which prohibits the eating of meat that was severed from a living animal (even if it was stunned and insensitive). This commandment given to Noah is recorded in Genesis 9:4: “But meat, with its soul [which is in] its blood you shall not eat.”

7. Establish Laws and Courts of Justice
This can be learned from the story of Shechem, Dinah, and the sons of Jacob. In Genesis 34:2 it relates, “Shechem, son of Hamor the Hivvite, the prince of the land, saw her; he took her, and he lay with her, and violated her.” His “taking” her against her will was a form of kidnapping, which was forbidden as a type of theft. Since the men of Shechem’s city did not convene a court of justice and convict him for his crimes, they failed to obey this commandment and also collectively became accomplices to his crime. Jacob’s sons therefore formed a court, convicted them, and executed them. It should also be noted that all the men of Shechem were also guilty of the sin of idolatry, as evidenced by the idols which the sons of Jacob removed from the city (Genesis 35:2,4). Also, note that Jacob called for the judgment of a court of law in Genesis 31:37.