Taking precautions means repairing the doors and windows of the house before it rains. It means to make preparations in advance to prevent accidents. From The Book of Songs - Bin Feng - Owl: "When it is not raining in the sky, we should penetrate the soil and prepare for our own homes."
Idiom allusions:
In 1046 BC, King Wu of Zhou destroyed the Shang Dynasty. In order to appease the adherents of the Shang Dynasty, he granted Wu Geng, the son of King Zhou, as a vassal in Chaoge, and his three younger brothers Guan Shu, Cai Shu and Huo Shu, respectively, in the east, west and north of Wu Geng, in order to monitor him.
King Wu's younger brother, Duke Zhou, Tai Gong, Zhao Gong and others helped King Wu destroy the merchants and made great contributions. King Wu left them in the capital to assist in politics, and Duke Zhou is the most trusted one.
Two years later, King Wu became seriously ill, and the ministers were extremely anxious. Duke Zhou specially offered a sacrifice to the ancestors of the Zhou Dynasty, saying that he was willing to die on behalf of his brother. He asked the king to bless King Wu's recovery. After the sacrifice, Duke Zhou sealed the toast in the stone room, and strictly ordered the historiographer not to reveal secrets.
It happened that the next day after Duke Zhou prayed, King Wu's illness began to take a turn for the better. Duke Zhou and other ministers were very happy. But soon, King Wu's old illness recurred and he died because of his overwork. The young prince Jisong was elected king, known as King Cheng of Zhou in history, and Duke of Zhou was ordered by King Wu to regent.
The regent of Duke Zhou aroused the dissatisfaction of Guan Shu and others. They spread rumors that the regent of Duke Zhou was to usurp the throne, which aroused the suspicion of King Cheng. Duke Zhou was unable to argue and left Kyoto.
Wu Geng, who was not reconciled to the demise of the Shang Dynasty, saw that there was a contradiction between the Zhou brothers, and sent someone to contact Guan Shu and others to stir up their relationship with the Duke of Zhou, while actively preparing for the uprising.
After two years of investigation, Duke Zhou finally found out the source of the rumor and learned about Wu Geng's preparations for rebellion. He was very anxious, so he wrote a poem named "Owl" to Cheng Wang. The main idea of the poem is: Owl Owl, you have taken my child, don't destroy my nest! Before it rains, I will peel Sangen's skin to repair the doors and windows. My hands are numb, my mouth is worn, and my feathers will fall, but my nest is still swaying in the wind and rain!
This poem, in the voice of a mother bird, reflects the Duke of Zhou's deep concern about the state affairs, but the young King Cheng did not understand the Duke of Zhou's painstaking efforts and was indifferent to it. Later, King Cheng accidentally found Duke Zhou's message in the stone chamber and was deeply moved. He immediately sent someone to invite Duke Zhou back to Haojing.
After Duke Zhou returned to Beijing, King Cheng sent him to fight against Uncle Three and Wu Geng. The resourceful Duke of Zhou soon quelled the rebellion and consolidated the rule of the Zhou Dynasty.
Later, people used the idiom "prepare for a rainy day" to refer to being prepared in advance.