《百战奇略·第九卷·离战》
凡是对敌作战，应当密切注视和利用敌国君臣关系中的矛盾，适时派遣间谍去离间他们。
凡与敌战，可密候邻国君臣交接有隙，乃遣谍者以间之。
When fighting against an enemy, it is important to closely observe and exploit the contradictions in the relationship between the enemy's monarch and his ministers, and send spies to sow discord when the time is right.