Grind an Iron Rod into a Needle

The Chinese idiom 只要功夫深，铁杵磨成针 (zhi3 yao4 gong1 fu shen1, tie3 chu3 mo2 cheng2 zhen1) literally means so long as you have put in a great deal of effort, you can grind an iron rod into a needle. It comes from 《方舆胜览》, a story about Li Bai (a famous poet in the Tang Dynasty (AD 618 - 907)) told by Zhu Mu in the Song Dynasty.

Born into a rich family in the Tang Dynasty, Li was second to none when it came to writing Chinese classic poetry. He had begun to write poems when he was only ten, but he was not a hardworking student and he tended to spend most of his time outdoors.

One day during his travels, Li saw an old woman grinding an iron rod on a big grindstone in front of a straw-thatched hut. Li asked the woman what she was doing. When the old woman told Li that she was making a needle, Li doubled up with laughter thinking the old woman had lost her marbles. The old woman reprimanded him and offered him some prescient words of wisdom

Don't laugh young man. As long as I keep grinding, I will make a fine needle out of this coarse rod someday.

Li Bai stopped to ponder her words and came to understand what she meant. Then, with great respect, he bowed deeply to the needle grinder and turned back toward home. After that day, Li became a very dedicated student and gave his undivided attention to his studies. His efforts paid off and he eventually became one of China's greatest poets.

Today Chinese speakers use the expression 只要功夫深，铁杵磨成针 (zhi3 yao4 gong1 fu shen1, tie3 chu3 mo2 cheng2 zhen1) (shortened to 铁杵磨成针 (tie3 chu3 mo2 cheng2 zhen1)) to encapsulate the idea that success is always possible if you work hard for a sufficiently long period of time. For English speakers the same idea is captured by the English idiom perseverence spells success.