《笑林广记·形体部》
属吏问禀告什么事，门客回答说： 老爷好一张光净屁股，多了一条蛔虫挂在外面。 
问禀何事，答曰： 爷好张光净屁股，多了一条蛔虫挂在外面。 
The subordinate asked what he was reporting, and the doorman replied, "Master, your butt is so clean, but there's a roundworm hanging outside."