This sentence used a metaphor. The fact that the Eight Treasures Congee was cooked in a pot implied that the Eight Treasures Congee had become very bad, even like a pot of porridge. " Let him sigh and boil in the pot " used a personification method to describe the state of the Eight Treasures Congee. It was as if it was constantly heating up but could not be completely heated up. People could not help but have a bad association. Therefore, this sentence vividly expressed a terrible situation through metaphor.