《新唐书·列传·卷一百一十七》
此时颜真卿在平原，早就听说安贼叛逆图谋，秘密蓄养了一批敢死之士做抵抗坚守之计。
时真卿在平原，素闻贼逆谋，阴养死士为拒守计。
At that time, Yan Zhenqing was in Pingyuan. He had heard about An Lushan's treacherous rebellion for a long time. He secretly trained a group of suicide squads as a means of resistance and defense.