Musar sobre Exodo 20:14

“You shall not covet your neighbor’s house” (Exodus 20:17); “and you shall not desire your neighbor’s house” (Deuteronomy 5:18). We were warned with this not to make evil plots to take the field or vineyard or anything of (your) [our] fellow, even if one gives their price. And we were warned about the thought of this evil thing, that we should not resolve in our thoughts to do it, as it is stated, “You shall not covet.” And if a person longs for his fellow to sell him a field or a vineyard or [any] of his possessions and [the owner] does not want to sell it - but if he pleads with him with many supplications, he will be embarrassed to answer him - it is forbidden to plead with him, as it is like coercion or duress. And one who covets to take any object and is a respected person - such that if he asked the question, they would not let his eminence down - it is forbidden to ask for [any] purchase or grant, unless he knows that [the owner] would give it to him with [full agreement], and not regret giving it to him in his heart.

Maimonides writes that the different wording used here as compared to the Tenth Commandment in Exodus 20,14 are not to be viewed as a mere repetition of the same commandment differently worded. The prohibition of לא תתאוה is a separate prohibition. The prohibition of לא תחמוד enjoins one not to acquire someone else's possession either by paying for it or by not paying for it unless the owner voluntarily agrees to sell it. The additional prohibition in our פרשה refers to the contemplation of ownership of such objects of one's desire. We must not ask how the Torah can expect us to exercise control over our mind's desires. This is a spurious argument. Only wicked people or fools would argue in such a way. Man is a free agent and can control his desires. He can discipline himself not to desire what is forbidden. G–d is well aware of our innermost thoughts and will punish people for sinful thoughts, whereas He will reward people who have pure thoughts for up to two thousand generations. It is best if a person can train himself to have only pure thoughts, for they lead to laudable deeds.

The מכילתא on Exodus 20,14 comments in a vein similar to what Maimonides has written. The commandment of לא תתאוה is seen as a preliminary stage to לא תחמוד. As long as the desire is not yet accompanied by plans to acquire the desired object, regardless of the owner's attitude, one is guilty only of לא תתאוה. As soon as one plans to obtain possession of the object of one's desire one becomes guilty of violating the commandment of לא תחמוד. How do I know that the plan to acquire someone else's property against his will eventually will lead to robbery? We know this from Michah 2,2: וחמדו שדות וגזלו , "They covet fields and seize them."