鞭长莫及 — “Beyond one's reach or power”

During the Spring and Autumn period, King Zhuang of Chu sent his minister Shen Zhou to visit the state of Qi. The route required passing through the state of Song. Normally, Song should have been informed in advance, but King Zhuang, arrogant about Chu's power, neglected to do so. The Duke of Song, upon learning this, was furious and detained Shen Zhou.

Minister Hua Yuan advised the Duke, saying, "Chu's failure to notify us beforehand implies they consider our state already annexed. We must uphold our sovereignty and dignity. Even if Chu attacks, we would rather fight to defeat than endure such humiliation!" Convinced, the Duke of Song executed Shen Zhou and prepared for Chu's invasion.

When King Zhuang of Chu heard the news, he indeed dispatched troops to attack Song, besieging its capital, Suiyang. The two sides were locked in a stalemate for several months, with Chu unable to achieve a decisive victory.

The following spring, Song sent its minister Le Ying to seek aid from the state of Jin. When Duke Jing of Jin prepared to send troops to assist Song, his minister Bo Zong advised against it, saying, "'Though the whip is long, it cannot reach the horse's belly.' How can we effectively intervene in Chu's affairs from such a distance?"