《汉书·传·赵充国辛庆忌传》
应派使者巡视边防部队预先作好准备，下令告诉各差人部落，不要让他们解除怨仇，以便查明他们的阴谋。 
宜遣使者行边兵豫为备，敕视诸羌，毋令解仇，以发觉其谋。 
An envoy should be sent to inspect the border troops and make advance preparations. An order should be given to the Charen clans, not to allow them to resolve their grievances, so as to find out their plot.