What do you mean by fireworks?

There is a mysterious ancient book in China, which is called Five Gong Jing. There is a saying in the book, "Fireworks in September, 999, the ice dust is dead", and people in Wuxi Mountain have pondered it over and over before they understand the meaning: "Fireworks in September, 999" means that there is a war every nine years, and 90 years is a reincarnation; "Chen Bing is a period of death" means that every 60 years, a king (the word death implies "king") will die or change dynasties.