《汉书·传·外戚传下》
籍武就把她们关进暴室。曹宫说： 您要好好收藏我儿子的胞衣，您知道他是什么样的孩子吗！ 
武迎置狱，宫曰： 善臧我儿胞，丞知是何等儿也！ 
Ji Wu locked them in the Violent Chamber. Cao Gong said: “You have to keep my son’s placenta safe. Do you know what kind of child he is?