"I suddenly realized the truth of art - it brings about the strongest effect and profoundest revelation with the simplest form and reason," Liu says.
He quoted the poem in his 1992 novella Country Teachers, which was an instant hit and became the first of the three-part Heavenly Mission years later.
Following the success of Country Teachers, Liu received a multitude of letters from enthusiastic readers, asking for a sequel. He thought the timing was wrong, until one day, when strolling on the street, he was struck by the name of an outdoor sports goods store, Heavenly Mission.
But the actual writing only took place after he learned about the life of Fan Xiaoxia, a country teacher in the mountainous region of Sichuan province.
Fan and her husband were both country teachers but taught in distant schools. During their 14 years of separation, the couple encouraged each other with characters in Country Teachers. They finally reunited in 2008, but Fan died a dozen days later in the disastrous Wenchuan earthquake.
During his 30-year writing career, Liu says he has persevered with the belief that the marrow of a novel is to reveal the elegance and dignity of human nature.