Confucius traveled around the world. Once he was short of food, he told Luz to beg for rice to cook porridge. When he was about to cook, Confucius saw that he had tasted it first, so he called him disrespectful to the teacher. But Luz was caught because the ashes on the beams fell into the pot, so he ate them. Confucius regretted after learning the truth and came to the conclusion that "seeing is not necessarily believing".