In Journey to the West, why was the old dragon beheaded when it rained less?

Although this old dragon only had a little light rain, it did break the rules of heaven in principle. You know, heaven is a very strict place. It doesn't care what kind of mistakes you made, and it doesn't care what reasons you made. If you make a mistake, God will punish you. Just like the old dragon here, although it just rained, it broke the dogma and had to be beheaded, which was not negotiable.

Although the immortals in the sky are powerful beings and the object of worship of the earth people, there is a difficulty that ordinary people can't understand, that is, there are very strict dogmas. For example, although the Dragon King is in charge of the rain on the earth, when and how much it rains are all decided by the above and must be carried out in accordance with the regulations.

As we all know, every year, a large-scale sacrifice is held on the earth to pray for good weather in the coming year. If people do anything against heaven, such as cursing God, God will punish mortals with floods and droughts. When mortals know that they are wrong, God will forgive them, and then call the Dragon King to rain on the earth. Moreover, every time it rains, the Dragon King will decide according to the actual situation of the people, and it is quite accurate every time. Just like big machines now, every part is carefully calculated. Once changed, the whole machine will change with it.

In the Journey to the West, King Jinghe was dissatisfied because he knew that someone could calculate the time, place and amount of rain. In principle, although he is dissatisfied with this, the rain is decided by the people in heaven. He, a king of many rivers, just did as required, and his dissatisfaction can only be suppressed.

But King Jinghe decided to oppose the Taoist priest and change the rainfall. Although he didn't succeed in fortune telling, he lost his life. Because he broke the dogma, he must pay for what he did.