The quote means that when attacking and plundering, one should be swift and unpredictable like fire, but when it comes to standing firm and defending, one should be unmovable like a mountain. In other words, the quote is encouraging the use of both aggressive and defensive tactics in warfare.
In pursuing business opportunities, be aggressive and dynamic like fire, but in protecting your assets and maintaining your position, be steadfast and immovable like a mountain.
In pursuing business opportunities, it is important to be aggressive and dynamic, just as fire is. This means that one should actively seek out opportunities, be willing to take risks, and be quick and flexible in adapting to changing circumstances.
At the same time, in protecting one’s assets and maintaining one’s position, one should be steadfast and immovable like a mountain. This means that one should be firm and determined in defending what one has already achieved, and not be easily swayed or deterred from one’s goals.
An example of being aggressive and dynamic in pursuing business opportunities might be a business that constantly seeks out new markets and partnerships, and is willing to try new and innovative products and services.
An example of being steadfast and immovable in protecting assets and maintaining position might be a company that has a strong and well-defended intellectual property portfolio, and is unwilling to compromise on issues such as pricing and product quality.