During the Spring and Autumn period, after Duke Dao of Jin ascended the throne, he aspired to restore Jin's prestige and dominate the feudal lords, much like his ancestor Duke Wen of Jin had done.
During the Spring and Autumn period, Duke Dao of Jin faced constant raids from northern tribes like the Rong and Di. Following his advisor Wei Jiang's counsel, he made peace with these tribes, securing his northern borders. He then sent envoys to befriend central plain states like Lu, Yan, Chen, and Song, and convened multiple alliances, boosting Jin's prestige. By achieving this, Duke Dao realized his ambition and became the hegemon of the central plain states.
At that time, the small state of Zheng kept switching alliances between Jin and Chu. Duke Dao of Jin grew furious, and in 562 BCE, he assembled troops from eleven states including Song, Lu, Wei, and Qi to attack Zheng. Duke Jian of Zheng was defeated and surrendered, sending Jin a massive tribute: a hundred war chariots, several court musicians, a collection of precious instruments, and sixteen skilled female dancers and singers.
Duke Dao of Jin was delighted and bestowed half of these gifts upon Wei Jiang, saying:
"Wei Qing, it was you who advised me to make peace with the Rong and Di tribes and stabilize the Central Plains states. For eight years, we have convened nine alliances of the feudal lords. Now our relations with all states are as harmonious as a beautiful melody. Zheng has sent these many gifts—let me share them with you!"
Wei Jiang replied, "Being able to live in harmony with the Di and Rong tribes is a blessing for our state. That you, my king, have become the leader of the Central Plains lords is due to your own talent—my efforts are insignificant. However, I hope that while enjoying peace and pleasure, you will also consider the future of our kingdom. The *Book of Documents* says: 'In times of stability, think of the dangers that may come; if you think ahead, you will be prepared; if prepared, disaster will not strike.' I offer these words as a reminder to you, my king."
Duke Dao of Jin was deeply moved and said, "I will certainly accept your advice. But rewarding meritorious officials is also proper. You must accept these gifts as well."
Wei Jiang had no choice but to accept the gifts bestowed by Duke Dao of Jin.
Later, the idiom "Preparedness Prevents Peril" came to describe that thorough advance preparation prevents misfortune.
Source: *Zuo Zhuan*, Chapter "Duke Xiang, Eleventh Year"
Meaning of the Idiom: Later, the Chinese idiom "有备无患" came to describe thorough advance preparation prevents misfortune.