Can you explain the metaphors used in Chapter 8 to describe the impermanent and unpleasant nature of the human body?

In Chapter 8, several powerful metaphors are used to illustrate the transient and base nature of the physical body. It is compared to the flame of a lamp, which looks the same from beginning to end but is actually different every single moment, highlighting the constant, unnoticed change from childhood to old age. The text describes the body as fleeting, stating that what is seen one moment perishes in the next. More starkly, as detailed in Chapter 8, the body is called a "washroom of excrement and urine, a foul place of phlegm, pus, and saliva," where death is an ever-present possibility, emphasizing its impurity and impermanence.