[Origin] This story comes from "Discourses of the States: Wu Language" (Guoyu · Wuyu).
[Interpretation] The idiom "as fierce as fire and as luxuriant as rushes" describes the grand scale and overwhelming momentum of a crowd or event.
At the end of the Spring and Autumn period, King Fuchai of Wu had successively conquered the states of Yue, Lu, and Qi. Filled with ambition, he continued his advance to the northwest, intending to conquer the state of Jin in one decisive stroke.
However, at this critical moment, King Goujian of Yue launched a surprise attack on Wu's rear. He led his army all the way to Wu's capital, Gusu (modern-day Suzhou), and dispatched troops to occupy the Huai River, cutting off King Fuchai's retreat route.
This news was like a bucket of cold water poured over King Fuchai's head. He was extremely shocked and immediately summoned his civil and military officials to discuss countermeasures. They argued that retreating now would mean defeat on two fronts and being attacked from both sides. However, if they could first defeat Jin, they would establish themselves as the undisputed hegemon among the feudal lords. Only then, they reasoned, would it be too late to deal with King Goujian of Yue.
With this major decision made, the immediate priority was to conquer Jin as quickly as possible. After careful consideration, they decided to win through an unexpected strategy.
One evening, King Fuchai issued his orders. The entire army ate a hearty meal, and the horses were well-fed. From the whole army, 30,000 elite soldiers were selected. They formed three rectangular battle arrays, each consisting of 10,000 men, arranged in ranks and files of one hundred each. The front of each row was led by an officer. Every ten rows (one thousand men) were under the command of a senior official (da fu). Each entire array was led by a general.
The central array, commanded personally by the King of Wu, wore white helmets, white armor, white clothes, carried white banners and white bows and arrows, and was known as the Central Army. The left array was entirely clad in red helmets, red armor, red clothes, and red banners, its redness as intense as a raging fire. The right array was uniformly black. They set out at midnight and arrived within one *li* (about 500 meters) of the Jin army by dawn. As the first light of day appeared, the Wu army beat their drums loudly, and their shouts of battle shook the heavens and earth.
The Jin soldiers awoke from their sleep and, upon seeing the three massive arrays of the Wu army and their overwhelming气势 (momentum), were utterly stunned: the white array looked like *tu* (a white flowering rush) — like a meadow covered in white blossoms; the red array looked like fire — like a fiercely burning flame; and the black array was simply like a vast, unfathomable ocean.