《后汉书·列传·方术列传下》
等到客人进屋，看到北墙上挂着十多条蛇，才知道华佗的医术奇妙。
及客进，顾视壁北，悬蛇以十数，乃知其奇。
When the guest entered the house and saw more than ten snakes hanging on the north wall, he realized that Hua Tuo had incredible medical skills.