《智囊(选录)·明智部·魏相》
魏相又因为许伯而专门告诉这些人要去掉副封，以防止密信被他们阻塞或隐藏。
魏相复因许伯白去副封，以防壅蔽。
Because of Xu Bo, Wei Xiang specifically told these people to remove the duplicate copy to prevent them from blocking or hiding the secret letter.