《伤寒论·伤寒例》
此外，地域有温凉高低不同，物体属性有刚有柔的差异，人们的饮食起居也不相同，病症与治法也应有别。
又土地温凉，高下不同；物性刚柔，餐居亦异。
In addition, different regions have different temperatures and altitudes, different objects have different qualities, such as hard and soft, and people's food and daily life are also different. Therefore, the symptoms and treatments will also be different.