《百战奇略·第五卷·害战》
诚如兵法所说： 能使敌人无法达到其预定目标的，是我设置重重障碍妨害它的缘故。 
法曰： 能使敌人不得至者，害之也。 
As the military strategy says: The reason why the enemy cannot achieve its intended goal is that I have set up many obstacles to hinder it.