《资治通鉴·晋纪·晋纪三十》
这时黄河上的冰还没有冻住，慕容宝以为北魏的部队一定不能渡过黄河来追击他们，没有派出侦察部队。
时河冰未结，宝以魏兵必不能渡，不设斥候。
At this time, the ice on the Yellow River had not yet frozen over, and Murong Bao thought that the Northern Wei army would not be able to cross the Yellow River to pursue them, so he did not send out a reconnaissance force.