《资治通鉴·汉纪·汉纪五十三》
公孙瓒军队屡战屡败。在此之前，有童谣说： 燕国南疆，赵国北界，中央不合，大如砺石，只有此中，可以避世。 
先是有童谣曰： 燕南垂，赵北际，中央不合大如砺，唯有此中可避世。 
Gongsun Zan's army suffered repeated defeats. Before this, there had been a rhyme: "South of Yan, north of Zhao, it won't align in the center; as big as millstone, this is the only shelter."