《淮南子·兵略训》
敌方如果掌握术数、准备周密，我方妄动就是自寻凶险；敌方以 虚 来对付我方的 实 ，我军也必定会被敌军擒获。
敌人执数，动则就阴。以虚应实，必为之禽。
If the enemy has mastered strategy and is well-prepared, then our side acting recklessly is seeking its own doom; the enemy uses "emptiness" to deal with our side’s "solidity", then my army will definitely be captured by the enemy.