《新唐书·列传·卷一百四十七》
咸通四年正月，南诏进攻紧迫，蔡袭将当年异牟寻的誓言系在箭上射入南诏军营。
四年正月，攻益急，袭录异牟寻盟言系矢上射入其营，不答。
In the first month of the fourth year of Xiantong, Nanzhao launched an urgent attack, and Cai Xi tied the oath of Yi Mouxun on arrows and shot them into the camp of the Nanzhao army.