《史记·三十世家·魏世家》
如耳见了成陵君说道： 从前魏军攻赵，断绝羊肠坂，攻克阏与，准备割裂赵国，把它分为两半，可是赵国所以没有灭亡，是因为魏国是合纵的盟主。
如耳见成陵君曰： 昔者魏伐赵，断羊肠，拔阏与，约斩赵，赵分而为二，所以不亡者，魏为从主也。
Ru'er went to see Lord Chengling and said: "In the past, the Wei army attacked Zhao, cut off the Yangchang slope, captured Yan Yu, and prepared to tear Zhao apart. However, Zhao was not destroyed because Wei was the leader of the allies."