《资治通鉴·魏纪·魏纪九》
有人说：以前，项羽强而汉高祖弱，互相交战，后来项羽与汉高祖约定中分天下以鸿沟为界，各归本土生息养民，张良认为民心一旦安定，就难以再发动，于是率兵追击项羽，终于消灭了他。
或曰：曩者，项强汉弱，相与战争，项羽与汉约分鸿沟，各归息民，张良以为民志既定，则难动也，率兵追羽，终毙项氏。
Someone said: Previously, Xiang Yu was strong and Emperor Gaozu was weak, they fought each other, then Xiang Yu and Emperor Gaozu agreed to divide the empire in two, taking the Honggou as their border, and each returned to their territory to rest and look after their people, Zhang Liang thought that once the people’s minds had settled, it would be difficult to rally them again, and so he led troops to pursue Xiang Yu, and he finally annihilated him.