Continuing the theme of desire that we introduced in the last posting, Judaic commentaries have often wondered about the famous proscription of the Decalogue: “You shall not covet” (Exod. 20:17). What exactly is Moses speaking about? This question has led many great rabbinic scholars to conclude that the Torah is not legislating a mere feeling; it is actually more concerned about action. Like many fleeting thoughts that come to our conscious mind in the course of a day, coveting is merely one feeling that our unconscious produces. Maimonides spells this point out:
“Anyone who covets a servant, a maidservant, a house or utensils that belong to a colleague, or any other article that he can purchase from him and pressures him with friends and requests until he agrees to sell it to him, violates a negative commandment, even though he pays much money for it, the Torah states, “Do not covet” (Exod. 20:14). This is not the kind of commandment that would be subject to corporal punishment, for the thought of coveting does not involve a deed. However, once a person takes possession of the article he covets, “Do not covet the gold and silver on these statues and take it for yourself” (Deut. 7:25), then he has transformed the thought of coveting into a deed . . .
Anyone desiring a home, a wife, utensils, or anything that belongs to another that he can acquire from him, is guilty of violating the biblical proscription regarding coveting–-from the time he thinks in his heart, “How is it possible to acquire this from him?” and his heart is aroused by this matter, as the Torah states “Do not desire” – “desire “ is directed only within the human heart.”
Thus according to Maimonides, there are two prohibitions: the covetous desire and the act that is involved in obtaining his neighbor’s property. Some rabbinic scholars differ. 
Maimonides adds, “The moment one entertains the thought how to obtain a neighbor’s possessions, e.g., a home, a wife, utensils, he violates the injunction against coveting, for the Torah makes it clear: “Do not desire….” (Deut. 5:18), for desire belongs to feelings of the heart and nothing else. Coveting is so serious because it leads to robbery. Should an owner refuse to part with his property, the one who covets may act upon his desire and decide to rob his neighbor of his belongings, as it is written, “They covet fields, and seize them; houses, and they take them; They cheat an owner of his house, a man of his inheritance” (Micah 2:2). In the event the victim stands up and attempts to rescue his property, the covetous man may decide to murder his victim, as we see in the story of Ahab and Naboth in 1 Kings 21:1-29.” 
On the other hand, Ibn Ezra asks a famous question: How can the Torah forbid a person to covet? Actions are surely easier to control, but how can one control a feeling? If one has a desire for something that another person has, is it reasonable to expect him to banish that desire?
Ibn Ezra provides an intriguing psychological response: Suppose someone told a greedy person that in a far-away kingdom, there are mountains of gold and precious gems, and that one could literally become wealthy by hauling off buckets of gold and jewels. Although he might desire such opulence, he would never indulge his fantasy by giving it serious thought since it is so far removed from him. In other words, consider whatever you desire to be unattainable and beyond your reach.
However, some Jewish medieval moralists take sharp issue with this point. One early 15th century rabbinic scholar (who kept his name anonymous) argues that the Bible is concerned about acting upon one’s impulses. It follows that the more one obsesses about another person’s wealth or belongings, the more one is apt to actually sin. Thus it is not the flickering thought of coveting that is forbidden here, it is when one seriously takes the time to actualize a sinful thought. The following story may serve as an example:
There was once a man who had a wicked neighbor whose property was separated from his own by a wall. This wicked man lusted after his neighbor’s wife and some of his possessions. On Friday, he heard his neighbor telling his wife: “I want to go away for the day on business,” and he did so. And so when the Sabbath arrived the wicked neighbor
What did this wicked man do? he through the thin partition separating his home from his neighbor; and by doing so, he violated the Sabbath. He then raped his neighbor’s wife and had his way with her. By doing so, he violated the law against coveting and adultery! But wait, he did not stop with only those three violations. While he was in the house, he decided to help himself to his neighbor’s property. His neighbor’s wife tried to stop him, and so he killed her. Now he violated the laws against stealing and adultery! Batting 1000, he went home and his parents reprimanded him for his awful behavior. The wicked man smacked his parents, and in doing so, he violated the law about honoring his parents.
After he was brought to court, he claimed somebody else broke through the wall, killed the woman stole the loot. All he did was reclaim personal property that he had “given” his neighbor for “safe keeping.” Now he violated the law against swearing falsely and for bearing false witness. Eventually, he was found guilty by the court. Eventually, he converted to paganism and completed his rejection of the Decalogue by violating the first two commandments to accept God as his personal God and to not worship idols.
All of this occurred because he could not control his lusts!!
And now you know the rest of the story.
 Maimonides, MT Hilchot Gzelah v’ Avedah 1:9. There are several other interesting laws Maimonides mentions regarding coveting, but in the interest of time, we will save them for a future posting.
 S’mag and Saadia Gaon consider coveting as only one general proscription. S’mag argues, “If Maimonides were correct, it would suggest that the Torah considered desiring a neighbor’s house to be as serious as desiring his wife! However, we must conclude that when the Torah utilizes the terms “desire” and “covet,” they must be understood as synonyms.”
 MT Hilchot Gzelah v’ Avedah 1:10-13.
 Orchot HaTsadikim Ch. 14, Sh’aar HaKinah (The Gate of Envy)