Deuteronomy 4:15

The foundation of true religion and morals is a right conception of the nature of God. In the first and second commandments of the Decalogue Israel had been taught the truths of the unity and spirituality of God. They are specially exhorted here to keep themselves from idolatry.

16-18. This prohibition probably refers to the animal worship of the Egyptians with which their fathers had been familiar in their bondage.