“You shall not make for yourself an image in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them; For I, the Lord you God, am a jealous God, punishing the children for the sin of the parents to the third and fourth generation of those who hate me, but showing love to a thousand generations of those who love me and keep my commandments.”
This commandment is relatively simple: No images. The people of God are to make no images of YHWH whatsoever, whether for use in worship, public display, or private devotion. (And obviously, based upon the first commandment, they are not to have any images of other gods, either.) Within their cultural context, this is a somewhat strange command. All the other peoples had prominent images, or idols, of their gods displayed in their temples and the public square. The ancients believed that the image, or idol, of their god contained its power and presence, and that it was a real, physical manifestation of the deity. For them, a god without an image would be no god at all.
However, there are two reasons why YHWH will not abide this practice.