《汉书·传·赵充国辛庆忌传》
敌人驻兵已久，放松了警惕，见到大部队，就丢弃了车辆辎重，想渡过湟水，路狭窄，赵充国就慢慢行军追赶敌人。
虏久屯聚，解弛，望见大军，弃车重，欲渡湟水，道厄狭，充国徐行驱之。
The enemy had been stationed there for a long time and had relaxed their vigilance. When they saw the large force, they abandoned their vehicles and supplies and wanted to cross the Huangshui. The road was narrow, so Zhao Chongguo pursued them slowly.