The seven-character quatrain "I compare my heart to the bright moon, and the bright moon shines on the ditch" comes from Mr. Qian Zhonglian, a famous expert in literature and history, and is included in the last line of "Chronology of Large Poetry in Qing Dynasty-Sweeping Leaves" (Volume 2 1), page106. But its original source no longer exists.
"I compare my heart to the bright moon, and the bright moon shines on the ditch" has been quoted too many times in China's modern and contemporary literary works, only a few words have been slightly changed, but the original intention is the same. It is more common in other people's comments and memoirs of famous scholars such as Li Qingzhao, Hu Shi and Lao She, and many intellectuals have also sung this sentence as a joke. There are also quotations in vernacular novels, plays, poems and couplets.
Although we can't get a satisfactory answer to this sentence, we can take this opportunity to go back to history and see that the poets in the Tang Dynasty "entrusted their hearts to the bright moon", while the people in the Song Dynasty later let the moon fall into the ditch, which is even more poetic.