This is an important set of so-called praying instrument, used by the monks when chanting their Sutras. It is found in all temples and through times, many do not know what this item is called, neither many do really knew the purpose it serves.................
A wooden fish (木鱼) sometimes known as a Chinese block, is a wooden percussion instrument. The wooden fish is used by monks and laity in the Mahayana Buddhist tradition. It is often used during rituals usually involving the recitation of sutras, mantras, or other Buddhist texts. The wooden fish is mainly used by Buddhist disciples in China, Japan, Korea, and other East Asian countries, where the practice of Mahayana, such as the ceremonious reciting of sutras, is prevalent.
Many legends describe the origin of the wooden fish - most take place in China. One says that a monk went to India to acquire sutras. On his way to India, he found the way blocked by a wide, flooding river. There appeared neither bridge nor boat.
Suddenly, a big fish swam up. It offered to carry the monk across the river. The fish told the monk that it wanted to atone for a crime committed when it was a human. The fish made a simple request, that on the monk's way to obtain sutras, he will ask the Buddha to guide the fish on a method to attain Bodhisattvahood.
The monk agreed to the fish's request and continued his quest for seventeen years. After getting the scriptures, he returned to China via the river, which was flooding again. As the monk worried about how to cross, the fish came back to help. It asked if the monk had made the request to the Buddha. To the monk's dismay, he had forgotten. The fish became furious and splashed the monk, washing him into the river. A passing fisherman saved him from drowning, but unfortunately the sutras had been ruined by the water.
The monk went home full of anger. Filled with anger at the fish, he made a wooden effigy of a fish head. When he recalled his adversity, he beat the fish head with a wooden hammer. To his surprise, each time he beat the wooden fish, the fish opened its mouth and vomited a character. He became so happy that, when he had time, he always beat the fish. A few years later, he had got back from the wooden fish's mouth what he had lost to the flood.
In Buddhism the fish, which never sleeps, symbolizes wakefulness. Therefore, it is to remind the chanting monks to concentrate on their sutra. Often the mallet used to strike the fish has a rubber ball tip to provide a muffled, but clear sound when struck.