One day, Duke Ai of Lu state received Confucius. After sitting down, he ordered the servant to bring a plate of peaches and a plate of common millet rice. Confucius ate millet rice first, then peaches. The attendants were snickering at him. Duke Ai asked, "We eat millet rice every day, but we don't often eat peaches. Why did you eat millet rice first and then peaches?" Confucius replied, "I know peaches are delicious, but I also know that millet is the main grain we eat, and is the main offering when we worship our ancestors. However, peach is in the lowest grade among fruits, and is not even qualified to enter the ancestral temple to worship our ancestors. So I eat millet rice first and then peaches. What's the problem with it?" Duke Ai was sincerely convinced by Confucius' explanation.