《菜根谭》修身篇 5 洁自污出 明从晦生（noble come from vulgar and wise come from stupid）

粪中至秽，变为蝉而引露于秋风；
腐草无光，化为萤而耀采于夏日。
因知洁常自污出，明每从晦生也。

翻译：在粪土中生活的幼虫是最肮脏的东西，可它蜕变成了蝉，便在秋风中吸食洁净的露水；
腐草本身不会发出光彩，可它孕育出的萤火虫却能在夏夜里闪烁。
因此我们可以知道：洁净的东西是从污秽中产生，光明的东西常常在黑暗中孕育。

The dirtiest worm of the world is maggot that live in feces, but they change to cicada and drink to dew of pure to live.
The grass of decay born to has not light,but they pregnant to glowworm could twinkle in dark night.
From my point of view : clean come from dirty and bright come from dark.