《旧唐书·本纪·卷九》
十九日，以封常清为范阳、平卢节度使、兼御史大夫，命令他招募兵士三万以抵御叛胡。
甲戌，以常清为范阳、平卢节度使、兼御史大夫，令募兵三万以御逆胡。
On the 19th, Feng Changqing was appointed Commissioner of Fanyang and Pinglu and concurrent Chief Censor and was ordered to recruit 30,000 soldiers to resist the rebel Hu.