It is said that this is a fable recorded in Zhuangzi. In the Song Dynasty, there was a man who kept a large number of monkeys at home. Everyone called him Xu Nigong. Xu Nigong understood the monkey's psychology, and the monkey also understood his words. Therefore, he loves these small animals that can communicate with people very much, and often reduces the rations at home to satisfy the appetite of monkeys. One year, there was a famine in the village, and Xu Nigong had to reduce the number of monkeys. When the monkeys heard that their food was reduced, they all stood up with their teeth bared, showing their anger. When the sniper saw it, he immediately changed his mind and said, "Well, I'll give you four in the morning and three at night. Enough! " When the monkeys heard that it had changed from three o'clock in the morning to four o'clock, thinking that food had increased, they all happily lay on the ground together and stopped making trouble. Later, people said from this fable that what the public said was an extension, and what they just said didn't count. Or when you do things, you often change, and what you just decided changes again in a short time. We call him "chop and change".