Duì gōngsī de cáichǎn, yuángōng bù gāi yǒu fēifènzhīxiǎng.
Employees shouldn't entertain illicit thoughts about company property.
Tips
history
Built around 非分 'not within one's portion/station'. 《新华成语词典》 (Xinhua Chengyu Dictionary) cites Lu Xun's 1934 essay 《花边文学·运命》 (Bianer Wenxue: Fate): 穷人买奖券，便是一种'非分之想' — 'a poor man buying lottery tickets is a kind of non-fenzhi-xiang' — meaning a desire for what isn't proportionate to one's lot. Classical usage extends back further but Lu Xun is the most-cited source.
usage
Almost always used negatively, paired with 别有 / 不该有 / 不要有 ('don't have...'). Common contexts: a man pursuing a woman improperly, an employee eyeing the boss's position or assets, anyone reaching above their station.
