《资治通鉴·汉纪·汉纪十》
现在，朝廷要征服西夷地区，诱使夜郎入朝称臣，降服羌人和人，攻取州，建筑城邑，进军匈奴腹地，烧毁匈奴的龙城，议事的大臣们都赞美这些行动和计划；但这只能让主持其事的大臣得到好处，对于国家来说不是好计策。 
今徇西夷，朝夜郎，降羌、僰，略薉州，建城邑，深入匈奴，燔其龙城，议者美之。此人臣之利，非天下之长策也。 
Now, the imperial court aims to conquer the western regions, entice Yelang to pay homage and submit to the court, subdue the Qiang and the Ren peoples, capture states, build cities, advance into the heartland of the Xiongnu, burn down the Xiongnu's Longcheng, and the court officials all praised these actions and plans. However, this can only benefit the ministers who are in charge, and it is not a good policy for the state.