《汉书·传·外戚传上》
留侯的儿子张辟彊是侍中，才十五岁，他对丞相陈平说： 太后衹有皇上这一个儿子，现在哭起来却不悲伤，您知道这是什么缘故吗？ 
留侯子张辟强为侍中，年十五，谓丞相陈平曰： 太后独有帝，今哭而不悲，君知其解未？ 
Liu Hou's son Zhang Piqiang was a waiter in the middle. He was only 15 years old. He said to Prime Minister Chen Ping: "The empress dowager only has one son, the emperor. Now she is not sad when she cries. Do you know why?"