《汉书·传·赵充国辛庆忌传》
到征和五年时，先零首领封煎等派人出使匈奴，匈奴再派人到小月氏，传言告诉各差人部落说： 汉朝的贰师将军带领十多万人投降了匈奴。
至征和五年，先零豪封煎等通使匈奴，匈奴使人至小月氏，传告诸羌曰： 汉贰师将军众十余万人降匈奴。
By the fifth year of Zhenghe, leaders of Xianling including Feng Jian sent envoys to the Xiongnu, who then sent people to Xiaoyue, spreading the rumor to said tribes, "The Han Dynasty's General Er Shi led over one hundred thousand people to surrender to the Xiongnu."