What do you mean, "As long as the kung fu is deep, the iron pestle is ground into a needle"

"As long as you work hard, the iron pestle is ground into a needle" means that any difficult thing can be successful as long as you are determined and willing to work hard.

Pestle: A stick used to beat rice or clothes; Just: conjunction. Indicates a necessary or sufficient condition.

Inspirational story: Li Bai, a great poet in the Tang Dynasty, didn't like reading when he was a child. On a stone by the river, he was inspired by an old woman who grinds an iron pestle to make a needle, and he understood the truth that "as long as Kung Fu is deep, the iron pestle is ground into a needle". Therefore, Li Bai studied hard and finally became a great poet, and was later called "Poet Fairy". Teach our children to persevere and study hard.