There is a poem titled "Owl" in allusion 1 "Book of Songs", which describes a female bird who has lost her child and is still building her nest diligently. There are several poems: "It's raining before it rains, so save for a rainy day. Today, the people will dare to insult her!" It means: before it rains, wrap the gap of the bird's nest with mulberry root skin as soon as possible. Only when the nest is firm will people be afraid of infringement.

Later, everyone extended these poems to "prepare for a rainy day", which means that everything should be prepared in advance so as not to be in a hurry.

Allusions 2 After the King of Wu destroyed, Guan Shu and Cai were sealed. Uncle Zhou Fuzheng was dissatisfied with the Three Supervisors. Guan Shu and others spread rumors that the Duke of Zhou would not be conducive to becoming a king. In order to avoid suspicion, the Duke of Zhou moved to Luoyi. Soon, Guan Shu and others colluded with Wu Geng, the son of Yin Zhou Wang. The Duke of Zhou was ordered to become a king, making an expedition to the east, killing Guan Shu, killing Wu Geng, releasing Cai Shu and collecting Yin Yumin. After Zhou's fair chaos, he wrote a song. Duke Zhou's poems are satirical, hoping that King Cheng would formulate measures in time to stop the rebellion and conspiracy. Although he was dissatisfied, King Cheng did not dare to blame him.