According to the law of Lu, the people of Lu are the slaves of the princes, and those who can redeem them will take money from the government. Zigong redeemed the people of Lu from the princes and gave them gold. Confucius said, "It was a mistake. Sages can change customs, but teaching can be applied to others, not just doing what they want. Nowadays, there are fewer rich people and more poor people in Lu, so it's no harm to take their money. If you don't take their money, you won't redeem others. " Lutz saves drowning people, who worship them with cows, and Lutz suffers greatly. Confucius said happily, "Lu people will save more drowning people!" " "

Above, from a secular point of view, Zigong does not accept ransom, which seems more noble than Lutz's cattle collection, but Confucius thinks Lutz is desirable and Zigong is not, so everyone knows that people should not only see the practice at that time, but also pay attention to its disadvantages; We should not only see the temporary benefits, but also focus on the permanent impact; We should not only see our own gains and losses, but also focus on the interests of the world.