Yan Yan, a disciple of Confucius, took his master's teachings on ritual and music to heart. When he became an official in Wucheng, he encouraged the people to play music and sing, filling the town with harmony.
Once, Confucius was traveling with several disciples and passed through Wucheng. Hearing the sound of zithers and singing everywhere, he smiled and said, "Why use an ox-cleaver to kill a chicken?"
Confucius's meaning was clear: Wucheng was a small place, and rites and music belonged to the great Way. Governing such a small place with the great Way of rites and music was like using an ox-cleaver to kill a chicken—making a mountain out of a molehill.
Yan Yan disagreed with Confucius's remark and questioned him, "Master, you once taught us that rulers who learn the way of rites and music will know how to love the people, and the people who learn it will become easy to govern. Is your teaching not applicable to Wucheng?"
Upon hearing Yan Yan's question, Confucius suddenly realized his mistake. Turning to his disciples, he said, "Pay attention—Yan Yan is right. When I said, 'Why use an ox-cleaver to kill a chicken,' I was only joking with him!"
Later, the idiom "Why use an ox-cleaver to kill a chicken" came to mean that a small problem does not require a big solution.
Source: *The Analects*, Chapter "Yang Huo"
Meaning of the Idiom: Later, the Chinese idiom "杀鸡焉用牛刀" came to describe a small problem does not require a big solution.