The allusion of "once again" comes from Bai Meng's "Technical Poetry" in the Tang Dynasty;
Chen Houzhu was the last emperor of the Southern Dynasties, and his sister Princess Lechang was both talented and beautiful. When she came of age, she married Xu Deyan, Chen Houzhu Sherman. After marriage, the two two of a kind, mutual respect. At that time, Emperor Wendi of Sui Dynasty had established the Sui Dynasty, and was ready to go south to destroy Chen. Xu Deyan and Princess Lechang agreed that if one day the country was destroyed and forced to separate, both sides would insist on finding each other so that they could meet again. So, they broke a bronze mirror in half and each took half as a symbol of reunion.
Soon, Emperor Wendi of the Sui Dynasty sent troops to destroy Chen Nan, and Princess Lechang was plundered into the home of Su Yang, the minister of the Sui Dynasty, because of her outstanding appearance, and was greatly loved. Every year during the Lantern Festival, Princess Lechang would ask her old servant to take half a bronze mirror to the market and sell it at a high price. And Xu Deyan, a few years later, because of the war, wandered to the capital Chang 'an.
On the fifteenth day of the first month, someone sold bronze mirrors at a high price. When he went to see them, he took out the other half of the bronze mirror he had brought, and he closed it twice. Sure enough, the second time around, I knew that his wife had become Su Yang's concubine. He was sad and angry, so he wrote a poem in front of the mirror: "The mirror went with people, but it didn't come back to people!" " Without the shadow of the moon, the moon is bright! "Princess Lechang saw this poem and knew that it was left by her husband Xu Deyan. She was very sad. Su Yang know, send someone summoned Xu Deyan, let them meet. However, at this time, Xu Deyan was down and out, and Princess Lechang had already become someone else's concubine. Princess Lechang was afraid to say a word when she saw Xu Deyan. Su Yang ordered Princess Lechang to write a poem, and the princess immediately wrote a poem: "Today, you move, and the new official will treat the old official. It's hard to be a man if you dare not laugh or cry. "
Touched by their true feelings, Su Yang immediately sent Princess Lechang back to Xu Deyan and presented a large amount of silver. Later, Xu Deyan and the princess returned to Jiangnan, and they grew old together.
This is the second story, which was greatly appreciated by later generations. Later, the relationship between husband and wife was compared to "the second time" and became the "patent" of husband and wife.