《资治通鉴·后汉纪·后汉纪四》
只要按兵不动守在城中，飞传诏书告诉他，观察他的志向，必定有解说道理，那君臣大礼就可以保全，千万不要轻易出去。 
但按兵守城，飞诏谕之，观其志趣，必有辞理，则君臣之礼尚全，慎勿轻出。 
As long as the army stays in the city and conveys the decree to him to observe his intentions, there must be a solution. In that way, the etiquette between the monarch and his subjects can be observed. Don't just go out rashly.