《资治通鉴·汉纪·汉纪三十八》
章帝这才应允，并亲手写诏赐给刘苍。诏书说： 骨肉之情，乃是天性，确实不因相隔远近而有亲疏之别。然而我们数次见面，感情愈重于昔时。想到大王久在京师劳累，希望能回国休养，我打算签署大鸿胪的奏书，却又不忍落笔，回望小黄门，授命传送此信。心中恋恋不舍之情，悲伤不能尽言。 
念王久劳，思得还休，欲署大鸿胪奏，不忍下笔，顾授小黄门；中心恋恋，恻然不能言。 
Only then did Zhangdi agree and wrote the imperial edict to Liu Cang with his own hand. The edict stated: The affection of our close relatives is a bond by nature, and can truly not be affected by distance. But now, every time we see each other, our affection deepens. I know that Your Majesty has stayed in the capital for a long time, and must be tired, and wish to return to your state's capital to rest. I had intended to grant the memorial of the Libationer, but could not bear to bring myself to do so. I glanced at the Imperial Attendant, and ordered him to deliver this letter. My heart is full of sadness and regret; my grief is beyond words.