《后汉书·列传·王刘张李彭卢列传》
王郎缘着这条线索诈称自己是真子舆，说： 我母亲本是成帝的歌女，有次下殿时突然仆倒，很快有一道黄气从上下通过，过了半天才苏醒过来，就这样怀了孕住在馆舍中，生子后赵后想谋害她，就用别人的婴儿将他换了，因而保全了生命。
郎缘是诈称真子舆，云 母故成帝讴者，尝下殿卒僵，须臾有黄气从上下，半日乃解，遂妊身就馆。赵后欲害之，伪易他人子，以故得全。
Wang Lang faked his identity along this clue and claimed to be the real Ziyu. He said: My mother was once Emperor Cheng's singing girl. There was a time when she suddenly fell when leaving the palace. Soon, there was a yellow aura passing through her up and down. After a long time, she woke up and became pregnant. Thus, she lived in the guest house and gave birth to a son. Later, Queen Zhao wanted to kill her, so she changed him with another baby, thus saving his life. 