Before God gave the Torah to Israel, He offered it to the rest of the nations of the world. They refused to accept it, each nation for its own reason.

When the Holy One, blessed be He, revealed Himself to give the Torah to Israel, it was not to Israel alone that He revealed Himself, but to all the nations. First He approached the children of Esau. He said to them: Do you accept the Torah? They said to Him: What is written in it? He said to them: “You shall not murder” (Exodus 20:13). They said: The very essence of those people [i.e., themselves] and their ancestor is murder, as it is stated in Isaac’s blessing to Esau: “By your sword you shall live” (Genesis 27:40). He approached the children of Amon and Moav. He said to them: Do you accept the Torah? They said to Him: What is written in it? He said to them: You shall not commit adultery (Exodus 20:13). They said: Our very essence is illicit relations.(Sifrei Devarim 343)