投鞭断流tóu biān duàn liú

中国前秦的苻坚进攻东晋时骄傲地说，我这么多的军队，把每个兵的马鞭子都投到江里，就能截断水流(见于《晋书·苻坚载记》)。后用来比喻人马众多，兵力强大。

英(of forces) numerous and powerful; with a strong army that,if the soldiers throw their whips into the river,it would be enough to stem the current;