纤尘不染

Explanation: Originally referred to the Buddhist practice, the excluded material things, to keep carefully clean. Now refers to is no hint of bad habits, bad atmosphere effects. Also used to describe very clean, clean. 　　Source: Tang, Buddhism, Taoism World "Fayuanzhulin" If the Buddha in the mountains through the line of dry soil, soil vain enough, with the Lan wind, blowing a ground-breaking hill, so scattered as dust, and even Yichen vain Does the body. "Song Zhang Lei," the twelfth lunar month after the snow garden Mui "spotless incense to the bone, Gushe fairy wind exposed body."