The 265th prohibition is that we are forbidden from using our thought to think up schemes of how to acquire something that belongs to our brother.

The source of this prohibition is G‑d's statement1 (exalted be He), "Do not envy (lo sach'mod) your neighbor's house."

The Mechilta says, "From the phrase 'Do not envy,' I might think the prohibition applies even if you just feel envy. But another verse2 says, 'Do not be envious of the gold and silver on them [i.e., idolatrous statues] and take it for yourselves.' Just as in that case the prohibition applies only when [because of his envy] he does an action, so too here it applies only when he does an action." This shows that the prohibition forbids carrying out schemes to acquire for ourselves one of our brother's belongings that we desire.

Even buying it at a high price is included in the transgression "Do not envy."