Musar к Рут 1:2

We know that the cause of Haman's decree was that the Jewish people at that time were guilty of two sins. One was a sin committed with their bodies, the other sin was committed with their souls. The sin committed with their souls was that they prostrated themselves before the image Nebuchadnezzar had constructed. The sin of committing idolatry is always considered as committed with one's soul, though one's body may have demonstrated it. As soon as one has made a conscious decision to make an obeisance to the idol, one's soul has already become guilty as if one had physically perpetrated the act. This is the only instance known in which G–d holds us culpable for the intention even though the act has not yet been committed. Our sages have derived this from למען תפוש את בית ישראל בלבם, "In order to take hold of the Family of Israel in their heart, etc." (Ezekiel 14,5). No such principle operates concerning any other kind of sins. Idol-worship is something that is committed primarily by the heart accepting an alien deity.