《汉书·传·李广苏建传》
等到燕王等因谋反被杀，穷究与他们同谋的人。苏武平素与上官桀、桑弘羊有交情，燕王也曾就苏武为国立功之事多次向皇帝申诉过，苏武的儿子又参与谋反，因此廷尉上奏请求逮捕苏武。
及燕王等反诛，穷治党与，武素与桀、弘羊有旧，数为燕王所讼，子又在谋中，廷尉奏请逮捕武。
After the King of Yan and others were executed for conspiracy, those who conspired with them were thoroughly investigated. Su Wu had always been on friendly terms with上官桀 and Sang Hongyang, and the King of Yan had also repeatedly appealed to the emperor about Su Wu's meritorious service to the state. Su Wu's son had also participated in the conspiracy, so the Minister of Justice requested the arrest of Su Wu.