2nd Commandment
It seems likely that the idols in view here are not those of pagan gods (the first commandment has proscribed them from Israel's worship), but representations of Yahweh himself. That was how surrounding nations depicted their gods, but such a theology had no place in the worship of Israel because it represented a fundamental confusion of the creation with the Creator.
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Far from being a help to worship, the idol sets up an insurmountable barrier to the refinement of human perception of what is spiritual.
John Mackay, Exodus, p. 344-345