《资治通鉴·唐纪·唐纪十八》
突厥人侵扰定州，刺史霍王李元轨命令打开城门，放下旗帜。突厥人怀疑有埋伏，畏惧而乘夜间天黑撤走。
突厥寇定州，刺史霍王元轨命开门偃旗，虏疑有伏，惧而宵遁。
The Turks invaded Dingzhou, and the prefect, King Li Yuangui of Huo, ordered the city gates to be opened and the flags lowered. The Turks suspected an ambush, were afraid, and retreated under the cover of darkness.