磨杵成针 mó chǔ chéng zhēn

DEFINITIONS

  1. to grind an iron bar down to a fine needle (idiom); fig. to persevere in a difficult task
  2. to study diligently

CHARACTERS

磨 mó grind; polish; rub; wear out; a millstone
杵 chǔ pestle; baton used beat clothes
成 chéng completed, finished, fixed
针 zhēn needle; pin; tack; acupuncture