Can you recommend two or four lines of poems with the words "rain" and "flat" as the hidden meaning of sweetness and eternity, because they have to be printed on the lighter? Thank you!

I recommend "Uchiha of the Country of Rain" and "Time Will Always Have You." In "Uchiha of the Country of Rain," the main character traveled to the Country of Rain, opened the Eternal Kaleidoscope, became a guardian angel, and led Akatsuki to create peace in the Shinobu. The plot related to rain was also in line with the protagonist's name (Xiao Nan) and the word "Ping". Although it did not directly mention "Xiao Yu", it could be associated with the image. "Time Will Always Have You" was mainly about the love story of Su Mu who had been waiting for Gu Beining. The word "rain" was not the main symbol, but it could be interwoven with the sorrow of "rain falling" in the middle of the text, implying that love could still maintain its sweetness for a long time after going through wind and rain. The final hidden poem: Meet in the rain, sweet and bitter equally; As time passed, love would never die.