During the late Spring and Autumn period, Fan Jishe of the Jin State fled his homeland.
One day, a man sneaked into Fan Jishe's home and spotted a large bell. Determined to steal it, he tried to haul it away on his back, but the bell was far too heavy to carry.
What to do? He thought for a long time and finally came up with a solution: smash the bell into pieces and take them home in batches.
So, he grabbed an iron hammer and struck the bell with all his might.
"The first strike produced a deep, resonant ring. Each subsequent strike echoed the same. The sound jolted him awake: 'If the bell rings, everyone will know I'm here. Then they'll take the bell and capture me.'"
Thinking himself clever, he came up with another idea: covering his own ears. That way, no matter how loud the bell rang, he wouldn't hear it. Since he couldn't hear it even from so close, others certainly wouldn't either, so he could safely steal the bell.
In truth, he was utterly foolish and laughable, deceiving himself. Though he covered his own ears and could no longer hear the bell's sound, others' ears remained uncovered, so of course they could still hear it ringing.
Later, people summarized this story into the idiom "covering one's ears while stealing a bell," used to describe self-deception.
Source: *Lüshi Chunqiu*, Chapter "Self-Knowledge"
Meaning of the Idiom: Later, the Chinese idiom "掩耳盗铃" came to describe self-deception.