《魏书·列传·卷八十八》
正始年间，世宗在东堂接见云的使者芮悉弗，芮悉弗向世宗进言说： 高句丽远在天际，世世代代对朝廷绝对忠诚，国内只有土地上出产的五谷，而对朝廷的贡奉却从无差错。
正始中，世宗于东堂引见其使芮悉弗，悉弗进曰： 高丽系诚天极，累叶纯诚，地产土毛，无愆王贡。
During the Zhengshi era, Emperor Sezong received Yun's envoy, Ruisifu, in the East Hall. Ruisifu said to Emperor Sezong: Goguryeo is far away in the sky, and it has been absolutely loyal to the imperial court from generation to generation. The domestic production is only five grains, but the tribute to the imperial court has never been wrong.