《新唐书·列传·卷一百一十》
黄巢平定后，皇帝要回京，李昌言因为自己是袭击郑畋夺了他的职务，现郑畋在朝中掌权，内心不高兴。因此三个人互相勾结，派使者告发郑畋的过错。
贼平，帝将还，而李昌言自以袭畋而夺之镇，今畋当国，内不喜，故三人相结，而遣客上畋过咎。
After the pacification of Huang Chao, the Emperor wanted to return to the capital. Li Changyan felt unhappy because he had attacked and replaced Zheng Tian, and Zheng Tian now was the one in charge of the Imperial Court. Due to this reason, the three colluded with each other and sent an emissary to report Zheng Tian's errors.