《资治通鉴·宋纪·宋纪三》
尚书令刘等人共同推举太史令张渊、徐辩向拓跋焘分析形势说： 今年是己巳年，恰恰是三种阴气聚集在一起的年分，木星突然靠近月亮，太白星出现在西方，不可以发动军事进攻，北伐一定失败，即使取胜，也对皇上不利。 
尚书令刘絜等共推太史令张渊、徐辩使言于魏主曰： 今兹己巳，三阴之岁，岁星袭月，太白在西方，不可举兵，北伐必败。虽克，不利于上。 
Liu and others, the Shangshu Ling, jointly nominated Zhang Yuan, the Taishi Ling, and Xu Bian to analyze the situation with Tuoba Tao, saying: This year is the year of Jisi, which is precisely the year when the three kinds of evil spirits gather together. Jupiter suddenly approaches the moon, and the Taibai star appears in the west. It is impossible to launch a military attack. The Northern Expedition will definitely fail. Even if you win, it will be disadvantageous to the emperor.