"Wooden fish" was originally created and popularized by Chinese Buddhism. It is one of the important "dharma tools" of Buddhism. In ancient times, it was called "wooden fish drum", "fish drum", or "fish plate". In Buddhist allusions, there are many legends about wooden fish.
In the Buddhist scriptures, there is a famous "fish belly" story, which says: In a Brahmin family in India, there was a child named Bokura. When he was very young, his biological mother died. His stepmother was very mean and often abused him.
Once, while his father was away, the stepmother threw him into the river and was swallowed by a big fish. This big fish was caught by a fisherman and brought to the market to sell. It just so happened that Bokura's father bought the big fish and took it home to prepare it for cooking.
Just as he was about to cut the fish with a knife, Bo Kuluo sang in the fish's belly: "May my father rest in peace, and don't hurt my son." His father quickly cut open the fish's belly lightly and rescued him. It is said that Bokura went through all kinds of hardships and finally became a disciple of Sakyamuni.

After this story spread to China, it was interpreted as another version. The plot of the story is basically the same, but it is stated as follows: When Master Xuanzang, an eminent monk in the Tang Dynasty, returned from the Western Regions, he passed through the land of Shu, met an elderly man, and went to his home to Huazhai. The elder's son was framed by his stepmother, thrown into the river, and devoured by a large fish.
It happened that Master Xuanzang wanted to eat fish that day, so the elder had to go out and buy a big fish. When cutting the fish, he rescued his baby from the belly of the fish. Master Xuanzang said: "This is exactly the karma of this child's long-cherished wish to keep the Buddhist precept of not killing, so even though he is swallowed by a fish, he will not die." The elder said, "How can I repay the kindness of the fish?" Xuanzang said. The commander said: "The fish sacrificed to save the child. It should be carved into the shape of a fish with wood, hang it in the Buddhist temple, and strike it every time you eat fast food, so as to repay the virtue of the big fish."
It is said that this is the origin of the use of wooden fish in Chinese Buddhist temples.

There is also a legend among the monks: as far back as the Han Dynasty, the emperor sent Master Ciguang and two monks to the West to get scriptures. An evil fish rushed towards the boat with its mouth open, and the scriptures on the bow were swallowed by the big fish. The two monks jumped into the sea to fight the big fish, killed the big fish and dragged it to the bow. In an instant, the wind was calm and the sun was shining brightly. The body of the big fish turned into sewage and flowed into the sea, leaving only the head of the fish on the bow. Master Ciguang returned to the Buddhist temple with the big fish head. In order to return the scriptures, he beat the big fish head every day and recited "Amitabha...". Day after day, the big fish head was knocked to pieces, and then I had to make a wooden one in the shape of the big fish head and beat it every day. In this way, knocking on wooden fish and chanting sutras has become a Buddhist habit.