wait till the yellow river runs clear water
As a Chinese idiom, the Pinyin is s ì h é zh ī Q ī ng, which means waiting for the Yellow River to clear. It's a metaphor for not being able to achieve what you expect. From Zuo Zhuan, the eighth year of Xianggong.
The origin of Idioms
In the eighth year of Xianggong in Zuozhuan, it is said in Zhoushi: "when the river is clear, how will life be?"
Idiom usage
Contraction; predicate; derogatory
Examples
What a "~" it is! On the bridge by Ye Shengtao
Chinese PinYin : sì hé zhī qīng
wait till the yellow river runs clear water
Make a success of the occasion. féng chǎng gān mù
the rich men dare not sit right under the eaves. zuò bù chuí táng
A book on the back of one's house. yǎng wū zhù shū
to catch a thief you must find the stolen goods. zhuō zéi zhuō zāng