《资治通鉴·汉纪·汉纪二十四》
定陶王上书辞谢说： 以我的才能资质，不足以充当太子。我愿暂时留住京师的定陶国邸，早晚进宫问安，等到皇上有了亲子，我就返回藩国守土。 
定陶王谢曰： 臣材质不足以假充太子之宫；臣愿且得留国邸，旦夕奉问起居，俟有圣嗣，归国守籓。 
The King of Dingtao wrote a letter of resignation, saying: "With my abilities and qualifications, I am not qualified to be a crown prince. I would like to temporarily stay in the Dingtao Palace in the capital, visit the palace morning and evening, and when your Majesty has a biological child, I will return to my fief to defend the land.