《贞观政要·卷九·论征伐》
既然陛下还没派使者前去查明虚实，只听岭南地方官的一面之词，就去攻打他，恐怕不明智，现在如果派人去打探，弄清真相，必然不会兴师动众，还可以使他自己上朝述职。 
此则反形未成，无容动众。陛下既未遣使人就彼观察，即来朝谒，恐不见明。今若遣使，分明晓谕，必不劳师旅，自致阙庭。 
Since Your Majesty has not sent an envoy to investigate, and only listening to one side of the story from Lingnan local officials, going to attack him is certainly not wise, if at this point we send someone to investigate and find out the truth, there will definitely not be a need to mobilize our forces, and we can have him report back to the court.