《史记·七十列传·白起王翦列传》
秦国将领李信，年轻气盛，英勇威武，曾带着几千士兵把燕太子丹追击到衍水，最后打败燕军捉到太子丹，秦始皇认为李信贤能勇敢。
秦将李信者，年少壮勇，尝以兵数千逐燕太子丹至於衍水中，卒破得丹，始皇以为贤勇。
Li Xin, a general of the State of Qin, was young and energetic and heroic and mighty. He once used thousands of soldiers to chase and kill Crown Prince Dan of Yan to Yanshui. In the end, he defeated the Yan army and captured Crown Prince Dan. Qin Shi Huang believed that Li Xin was virtuous and brave.