《资治通鉴·汉纪·汉纪三十六》
祭肜说： 你们要是真想立功，就应当回去打匈奴，斩下匈奴首领的头送来，我才会信任你们。 
肜曰： 审欲立功，当归击匈奴，斩送头首，乃信耳。 
Ji Rong said: If you really want to do something to establish your merits, you should go back and fight the Xiongnu, cut off the heads of the Xiongnu leaders and send them to me, and then I will trust you.