《资治通鉴·汉纪·汉纪一》
怀王曾与各路将领约定说： 先打败秦军进入咸阳城的人，在关中为王。 
怀王与诸将约曰： 先破秦入咸阳者，王之。 
King Huai had made an agreement with the generals of all the roads: whoever defeated the Qin army first and entered Xianyang, would be king in Guanzhong.