This is a poem by China, in which "past dust" refers to past lives and past experiences; "Bashu" here refers to the Bashu area in history, which is today's Sichuan Basin; "Like a dream" means that life is short and like a dream; "This life" refers to this life, the life at this moment; "Tangmen" refers to the famous Tang Sect in martial arts novels, which is famous for its poison and hidden weapons.
Although my previous life was short as a dream, I don't regret joining the famous Tang family in this life. This poem expresses the author's loyalty and firmness to Tangmen and his understanding of his short life.