《宋史·列传·卷一百一十九》
宗泽踏冰渡过黄河见到康王，说京城被围困很长时间，救援京城不可缓慢。
泽履冰渡河见王，谓京城受围日久，入援不可缓。
Zong Ze crossed the Yellow River on ice to meet King Kang and said that the capital had been under siege for a long time, so it was imperative to rescue it without delay.