《北史·列传·卷四十三》
元康说： 前次敌人从沙苑退兵，他们尚且没有埋伏，现在是失败逃跑，怎么会有预先设下埋伏的深谋远虑？
元康曰： 前沙苑还军，彼尚无伏，今者奔败，何能远谋？
Yuan Kang said: "The last time the enemy withdrew from Shayuan, they didn't lay any ambushes, and now that they are fleeing after defeat, how could they have thought so far ahead as to set up an ambush?