《宋史·列传·卷二百三十》
回来后，神色不变，苏轼抚着他的背说 ：你他日必能杀人。 章惇问 ：为什么？ 
进士登名，耻出侄衡下，委敕而出。
After returning, his look did not change. Su Shi patted his back and said: "You will definitely become a murderer in the future." Zhang Dun asked: "Why?"