《资治通鉴·隋纪·隋纪六》
当时，右骁卫大将军来护儿率领水军从东莱将要入海进兵平壤，杨玄感派家奴伪装成东方来的使者，诈称来护儿谋反，六月，乙巳，杨玄感进入黎阳，关闭城门，大肆索要男夫，用帆布制成头盔铠甲，任命官员僚佐，都按隋文帝开皇年间的旧制，他向附近各郡发送文书，以讨伐来护儿为名，命令各郡发兵在黎阳仓集结。
时右骁卫大将军来护儿以舟师自东莱将入海趣平壤，玄感遣家奴伪为使者从东方来，诈称护儿反。六月，乙巳，玄感入黎阳，闭城，大索男夫，取帆布为牟、甲，署官属，皆准开皇之旧。移书傍郡，以讨护儿为名，各令发兵会于仓所。
At that time, General Lai Huer of the You Xiao Guards led the navy from Donglai and was about to enter the sea to advance and attack Pyongyang. Yuang Xuanji sent a family slave disguised as an envoy from the East, falsely claiming that Lai Huer was rebelling. In June, on day Yi-si, Yuang Xuanji entered Liyang, closed the city gates, and requisitioned many men to make helmets and armor out of canvas. He appointed officials and assistants, all according to the old system of Emperor Wen of the Sui Dynasty. He sent out documents to the various nearby counties, ordering them to send troops to gather at the Liyang granary in the name of attacking Lai Huer.