הלכה אויף דברים 5:18

If you covet the house or the vessels of your neighbor, or anything which your neighbor has no intention of selling, and you ask his friends to influence him, or if you, yourself, pressure him until he agrees to sell it to you, you have violated the injunction, "You shall not covet."⁶Exodus 20: 14. From the moment you were tempted, and began to think, how will you acquire this item, you have violated the command, "You shall not desire";⁷Deuteronomy 5:18. for desire is only in the heart, and desire leads one to covet. If you ultimately buy that which you had desired, you will have transgressed two negative commands. That is why it is said, "You shall not covet" and "You shall not desire."⁸These are two separate negative commands.

Not to lust, as it is said, “Neither shalt thou… desire thy neighbour’s house…” (Deut. 5:18).

Not to desire the money of your friend: That we were prevented from fixing in our thoughts to desire what is in the hand of one of our brothers, the Children of Israel; since the fixing of the desire for that thing in our heart will become a cause to create machinations to get it from him — even though it is not his will to sell them — by purchase or exchange or, if we cannot [acquire it] in any other way, by force. And about this is it stated (Deuteronomy 5:18), “you shall not desire the house of your neighbor, etc.” And Rambam, may his memory be blessed, wrote (Sefer HaMitzvot, Negative Commandments 266), that the two negative commandments — which are “you shall not covet,” which is in the Order of Vayishma Yitro, and “you shall not desire” in this Order — are not repeated negative commandments about one matter. Rather, they are two matters. As the negative commandment of “you shall not covet” will prevent him from taking that which someone besides him acquired, in any way — whether with money or without money — if [the owner] does not want to sell that thing. But this negative commandment of “you shall not desire” will prevent him from even the desire for it in his heart. As with the desire, he will come to supplicate him and to pressure him to sell it or trade it for another vessel, no matter what. And even though one of these negative commandments brings its fellow, they are considered two nonetheless. And behold, you [can] see the difference between them.