《新唐书·列传·卷一百三十七》
当初，朱滔因刘怦忠诚有勇，使他任范阳留守，到自己兵败，怕他会谋害自己，彷徨不敢入城。
初，滔以刘怦忠力，使留守，及败，疑图己，仿徨不敢入。
At the beginning, Zhu Tao had sent Liu Peng, who was both loyal and brave, to guard Fanyang. However, when Zhu Tao was defeated, he feared that Liu would try to harm him and he hesitated and didn’t dare to enter the city.