《资治通鉴·唐纪·唐纪八十一》
当初，朱全忠自凤翔迎接昭宗车驾返回长安，见德王李裕眉目清秀，并且已经成年，很厌恶他，私下对崔胤说： 德王曾经窃据帝位，哪里能够再留下！
初，硃全忠自凤翔迎车驾还，见德王裕眉目疏秀，且年齿已壮，恶之，私谓崔胤曰： 德王尝奸帝位，岂可复留！
At that time, Zhu Quanzhong personally welcomed Emperor Zhaozong back to Chang'an from Fengxiang. Seeing that Prince De, Li Yu, had clear eyes and fine features, and was already an adult, he loathed him. He spoke to Cui Yin in private: "Prince De was a thief who usurped the throne, we cannot keep him alive!"