Lei Feng, styled Songcun and known by the pseudonym Lüju, was the son of Lei Yixian, hence he named himself Shaoyi. A renowned physician of the Qing Dynasty, he was born in the 17th year of the Daoguang era, originally from Pucheng, Fujian Province, and passed away in the 14th year of the Guangxu era (1837-1888), at the age of 52. He studied medicine under his father from a young age and was exceptionally intelligent, surpassing his father in medical fame. Feng was skilled in observing and summarizing in his medical practice. He read extensively from various schools of thought, often able to draw parallels and understand the constant and the variable. His work, Shibing Lun, is based on the Neijing's section "Injury by cold in winter leads to warm diseases in spring..." (from the "Yin-Yang Yingxiang Dalun") as its guiding principle, incorporating teachings from ancient sages and later scholars, combined with his personal insights. He first treated diseases by discussing their constants; then, through practical cases, he discussed their variables. This approach enabled him to "know the constant and understand the variable, making seasonal diseases not difficult to treat" (from the preface of Shibing Lun). His disciples, such as Cheng Xi and Jiang Cheng, also gained fame in medicine.