《明史·列传·卷一百四十四》
朝廷又决定要讨伐朝鲜，自严说不能立即讨伐它，应当等它请求上贡，表示忠诚，为我们的东征效力，现在只要慢些答应给它加封就是了。
又议讨朝鲜，自严言不可遽讨，当俟请贡输诚，东征效力，徐许其封耳。
The Imperial Court also decided to attack Joseon. Ziyuan advised against launching an immediate attack. He argued that the court should wait for Joseon to request to pay tribute, as a sign of allegiance and to contribute to our expedition in the East. He stated that they should delay their promise to grant Joseon a higher nobility rank.