During the Three Kingdoms period, the brilliant statesman Cao Cao was not only a skilled poet and writer himself but also gathered many talented literary figures around him. Among them, the renowned writer Chen Lin stood out as a particularly prominent member.
Chen Lin originally served as a scribe under the northern warlord Yuan Shao, a man of immense ambition commanding a formidable army. As Cao Cao's power grew, Yuan Shao felt threatened and decided to launch a campaign against him. To rally support from other warlords, he ordered Chen Lin to draft a fiery proclamation denouncing Cao Cao.
Chen Lin immediately drafted a proclamation, writing with unrestrained vigor, enumerating Cao Cao's various "crimes" and even mercilessly ridiculing three generations of Cao Cao's ancestors.
Cao Cao often suffered from severe headaches. One day, as another attack struck, an attendant brought him a war proclamation drafted by Chen Lin. Though the content infuriated him, Cao Cao was captivated by its brilliant prose. He exclaimed, "What magnificent writing! Reading this has cured my headache!"
When he learned that the drafter was Chen Lin, a clerk under Yuan Shao, he couldn't help but sigh, "What a pity that such a talent cannot serve me!"
Later, Yuan Shu's arrogance and incompetence led to his defeat by Cao Cao. Chen Lin then defected to Cao Cao. When Cao Cao saw Chen Lin, he asked, "Back then, when you wrote the denunciation against me for Yuan Shu, it would have been enough to curse me alone. Why did you have to curse three generations of my ancestors?"
Chen Lin apologized, "At that time I served under Yuan Shao, and when he ordered me to write, I had no choice—like an arrow on the bowstring, it had to be shot!"
Cao Cao couldn't help but laugh at that. From then on, he never brought up the old grievance again. Impressed by Chen Lin's talent, he appointed him as his chief secretary, and many of Cao Cao's official documents were later penned by Chen Lin himself.
Later, the idiom "an arrow on the bowstring" is often used together with "must be shot," meaning a situation has reached a point where action is unavoidable, or words must be spoken.
Source: *Book of Wei*
Meaning of the Idiom: Later, the Chinese idiom "箭在弦上" came to describe a situation has reached a point where action is unavoidable, or words must be spoken.