dredge the moon out from the bottom of the water
As a Chinese idiom, the Pinyin is Shu ǐ D ǐ L ā oyu è, which means that you can only waste your efforts to do something you can't do at all. From chuanxilu.
The origin of Idioms
Wang Shouren's chuanxilu of Ming Dynasty says: "if you want to seek the sound of yuan in the grain of Jiahui millet, it's like fishing for the moon at the bottom of the water."
Idiom usage
In vain; in vain.
Chinese PinYin : shuǐ dǐ lāo yuè
dredge the moon out from the bottom of the water
fierce struggle between two evenly-matched opponents. hǔ dòu lóng zhēng
wrinkled skin and white hair -- advanced in age. jī pí hè fà
Obedience is better than respect. gōng jìng bù rú cóng mìng
hills as if smiling in spring. chūn shān rú xiào