▶ In the late stage of the Spring and Autumn Period (春秋 chūn qiū,770 - 221BC), Fu Chai (fū chāi 夫差),ruler of the State of Wu (wú guó 吴国),defeated the states of Yue (yùe guó 越国),Lu (lú guó 鲁国) and Chi (qí guó 齐国) consecutively. After the previous overwhelming victories,the ambitious king looked forward to another success-- putting the State of Jin (jìn guó 晋国) into his own pocket.
But the timing turned out to be not good,it was when Fu Chai led his self-claimed invincible army to State of Jin,Gou Jian (gōu jiàn 勾践),king of the State of Yue,attacked him by surprise in the rear. Gou Jian's army fiercely fought their way to Gu Su (gū sū 姑苏),capital of the State of Wu. What’s more,Gou Jin took whole control of the Huai River (huái hé 淮河) as soon as he arriving Gu Su,thus cutting off Fu Chai's retreat road.
The bad news really took Fu Chai aback since the move taken by Gou Jian was never expected. So Fu Chai immediately called on his brain tank,altogether,to figure out a way to deal with this urgent situation. Once they decided to withdraw from Jin ,they would be assaulted by both the Jin army and the Yue army,putting themselves in a very passive situation. But,if they chose another way around-- defeating the State of Jin firstly,then Fu Chai would become the most powerful leader among all the leaders,at that time,it would be a pice of case for Fu Chai to do with Gou Jian. After a hot debate and comprehensive consideration,Fu Chai made his minds to launch a sudden attack to the State of Jin as quickly as possible.
One day,before the nightfall was coming,Fu Chai issued his instruction. The officers and men of the whole army ate their fill,and the steeds were well fed with fodder. 30,000 officers and men were chosen from the whole army to form three phalanxes,with 10,000officers and men respectively. The solders in the middle phalanx wore white suits of armour,and carried white flags and white bows and arrows,and they were led by king of the State of Wu Fu Chai himself. The other two phalanxes were led by senior generals. The soldiers in the left phalanx wore red suits of armour,and carried red flags and red bows and arrows.
Awakening from their dreams,the solders of the Jin army were totally shocked by the magnificent scenery outside. The white phalanx was like a field covered with flowering rush,the red phalanx was like a burning fire,and the black phalanx was simply like a bottomless sea.Being badly terrified by the large scale army,they surrender to Fu Chai without fighting,just as he munipulated.
Since then,people use the phrase "like fire and flowering rush"to refer to significanlty tremendous momentum of certain event.