A king with his pond

Once a king told his people to dig a tank. When the tank was dug, the king announced that a glass of milk should be brought from every house in the kingdom. And at night it has to be put in the tank. In the morning the king wants to see his tank filled with milk. After hearing the king's order, everyone returned to their homes. A man was preparing to take milk to the king's pond at night. At that time a thought came to his head. He thought. Since everyone will give a glass of milk in the king's pond. If I give a glass of water instead of milk, no one will be able to catch it. Because everyone will give milk late at night. No one will understand what I am giving in the darkness of night. Everyone will think I am giving milk. Thinking this, the man thought to himself, I will give water instead of milk.

He went early in the night and brought a glass of water to the king's pond. The next day the king came to see his milk pond. The same pond is full of water. No sign of milk can be seen here. The king's pond is full of water. In fact, everyone thought that someone else would give milk, so I gave them water. Thus the king's pond was filled with water.