《水经注·卷二十》
弟子到了霞萌，随从与关吏发生争执，被打伤了。他打开小盒，见一张字条上写道：打破了头的人，可用此药敷上。
生到葭萌，从者与津吏诤，打伤，开笥得书，言其破头者，可以此药裹之。
The disciple arrived at Xia Meng, and his entourage had a dispute with the customs officials and was injured. He opened the box and saw a note saying: If your head is broken, you can apply this medicine.