It is said that during the Spring and Autumn period in the state of Qi, Duke Huan of Qi was reading aloud in his hall one day, the sound of his recitation drifting down. Bian, a wheelwright busy making wheels below, grew somewhat annoyed, put down his hammer and chisel, and approached to ask, "May I ask what book you are reading?"
Duke Huan, seeing his abrupt manner, felt somewhat displeased but still replied, "I read only the books of the sages." "Are those sages still alive?" "Of course, they died long ago." "Oh, if they are already dead, then what you are reading is nothing but the dregs left behind by the ancients!"
Duke Huan was taken aback by his bluntness and flushed with anger, saying, "I am reading here—how dare a craftsman like you casually criticize? I ask you: why are the words left by the ancients all dregs? If you can explain yourself today, fine; if not, I will have you executed immediately!"
Lun Bian stroked his beard and calmly replied, "Your Majesty, please calm your anger. I am merely sharing a simple thought based on my craft of making wheels. For instance, when carving a tenon with an axe, if it is too small, it will be loose and unstable in the mortise; if too large, it will be tight and impossible to fit. Only when it is neither too big nor too small, neither too loose nor too tight, can the two fit perfectly and hold firm. This skill is mastered by hand and felt in the heart, but it cannot be expressed in words—there is a subtle mystery within it. I cannot teach it to my son through speech, nor can he inherit it from me, which is why I am still making wheels for a living at seventy. The profound and unique insights of the ancient sages cannot be passed down through words; they inevitably vanish with their deaths. So, what you are reading now, if not the useless dregs of the ancients, what else could it be?"
Duke Huan listened and found some truth in Wheelwright Bian's words, so he pardoned the man's impertinence.
"The idiom 'De Xin Ying Shou' means the hand follows the heart's intent, describing great skill and effortless execution."
Source: *Zhuangzi*, Chapter "The Way of Heaven"
Meaning of the Idiom: Later, the Chinese idiom "得心应手" came to describe how the hand follows the heart's intent, describing great skill and effortless execution.