《汉书·纪·高帝纪上》
足下如果整日强攻，双方伤亡定会很多；要是放弃攻宛而引兵向西，宛地的秦兵完全尾追于后。
今足下尽日止攻，士死伤者必多；引兵去，宛必随足下。
If your highness were to exhaust troops and launch a non-stop attack, there are bound to be many casualties on both sides. On the other hand, if you were to give up attacking Wancheng and lead your troops west, the Qin army in Wan would pursue you.