《史记·三十世家·孔子世家》
有一次孔子正敲着磬，有个背着草筐的人路过门口，说道： 有心思啊，就敲打石磬啊！
孔子击磬。有荷蒉而过门者，曰： 有心哉，击磬乎！
One day, Confucius was beating the qing, and a person carrying a pile of grass walked past the door and said, “What a mind, hitting the stone qing!”