《宋史·列传·卷一百三十三》
又进言请求将都城设在建康，说： 汉高祖进入关中，光武帝刘秀守卫信都，大抵与人作战，不扼敌人咽喉，不打击敌人侧背，不能获得全胜。
又进言乞都建康，谓： 汉高入关中，光武守信都。大抵与人斗，不搤其亢，拊其背，不能全胜。
He also requested that the capital be moved to Jiankang, saying: Emperor Gaozu of Han entered Guanzhong, and Emperor Guangwu of Han defended Xinye. These basically mean that when fighting against enemies, if one does not control the enemy's throat or attack the enemy's flank, one cannot achieve complete victory.