In the first of His ten incarnations, God Vishnu took the form of Matsya (a fish) to save the first man Manu from the deluge or maha pralaya that consumed the world.
The story goes like this. During the Satya Yuga, King Manu, a devout follower of God Vishnu, found a tiny fish while performing rituals by a river. The fish begged for protection from the bigger fishes. King Manu, being a compassionate and righteous ruler, decided to save the fish. He put it in a small pot and took it home.
However, by the next day, the fish had outgrown the pot. Realizing that it needed a larger space, King Manu transferred the fish to a bigger container. But the fish continued to grow, and soon it outgrew the container as well. He transferred it to a pond and the fish outgrew the pond as well. The fish continued to grow bigger even after it was transferred to a river, so was put into the ocean.
The king realized that it was God Vishnu himself and eventually, the fish revealed its divine identity as God Vishnu.
God Vishnu instructed Manu to build a massive boat to save the world from an impending cataclysmic flood. Manu obeyed, taking with him the Seven Sages (Saptarishi), seeds of all plants, one of every animal species, and the sacred Vedas. Torrential rains poured, rivers surged, and oceans swelled, causing a catastrophic deluge that submerged the Earth. Only Manu’s boat, guided by God Vishnu in the form of a fish, survived the flood.
The fish’s horn towed the boat to the peak of the himalayan mountain as the waters receded. Manu, the sages, animals, and Vedas disembarked, and they began the task of repopulating the Earth and restoring knowledge and righteousness.
