Three Thousand Swordsmen
During the Warring States Period, King Huiwen of Zhao State was very fond of fencing, and supported more than three thousand swordsmen who were good at fencing. They fought with each other in the palace day and night, with a result of more than a hundred killed and injured every year. But King Huiwen was still keen on it. Because of that, many people of Zhao State were busy practicing fencing skills, and few cared for farming and production; therefore, the nation's power was influenced.
It was not until one day when the prince dispatched someone to invite Zhuangzi to the palace to persuade the king that he gave up such a hobby.
Now, we usually use this idiom to indicate that one has a large number of soldiers or the retainers.
We can keep our own hobbies, but should not indulge in them. If we can't control ourselves, these hobbies will bring us more harm than benefit.