Chinese idiom · 成语
投鞭断流
Meaning
Toss whips to stop a river; overwhelming might.
Character by character
Origin and story
Historical accountBefore attacking Eastern Jin, the Former Qin ruler Fu Jian dismisses warnings about the Yangtze's defensive strength. In the account preserved in the Book of Jin, he boasts that his troops are so numerous that throwing their riding whips into the river would stop its flow. His adviser Shi Yue urges caution, arguing that earlier defeated rulers had weaknesses Jin did not share.
The boast is a metaphor for immense numbers, not an event in which soldiers actually dammed a river. Fu Jian's subsequent defeat at the Fei River gives the story an ironic edge: numerical strength did not guarantee victory. The idiom can evoke either a vast army or overconfidence in one.
Sources and further reading
In everyday life
电影中的大军虽有投鞭断流之势，却因轻敌而败。
The film's enormous army looks overwhelming, yet loses because it underestimates the enemy.
Literary description of vast military numbers; the source story also warns against overconfidence.