1)    Anyone who cherishes and desires a house or portable property belonging to someone else, or anything else belonging to someone who is unwilling to sell it, and the first person pressures him and sends him messengers to pressurize him until in the end he sells the object has transgressed a biblical negative commandment, as it says “You may not desire!”. (Kitzur Shulchan Aruch 182)

2)    From that moment that he starts to be persuaded and to wonder how he can possibly acquire that object he has transgressed the prohibition of “You shall not want!”, and when he brings the matter to a close and actually acquires the object he has also transgressed the prohibition of “You may not desire!”. (ibid)