Matsyavatra - Story of Agni Puran
It is a tale of old time: A brave, adventurous and brilliant king named Satyavrat ruled a country named Dravid. He was a dedicated devotee of Lord Narayan. His mind was perpetually dedicated to the devotion of Shri Vishnu.
One day he was offering oblation in the river named Kritmala. At that very time a small fish fell into his hands. Satyavrat dropped it back in the river out of compassion. At this, the fish said in pitiful voice, "Hey king! You are very kind. You are aware of the fact that the large creatures of water feed on the smaller species of their kind. Why are you leaving me here then? I am in your shelter out of their dread. Therefore protect a trifle creature like me."
On hearing the entreaty of the fish, Satyavrat said, "Fish! Do not worry. The one who comes to my refuge does not return disappointed. I promise that I will protect you. My kamandalu (holy pail) itself has enough space to accommodate a small fish like you; you can live in it without fear. You will not require to move anywhere else." Saying this, Satyavrat took resolve to protect the fish and allowed her to live in the kamandalu.
But the size of the fish grew so huge that the kamandalu was not adequate to accommodate her. Then she said to Satyavrat, "Hey king! You had selected the kamandalu to accommodate me but this kamandalu has become very small for me. I cannot live in it. Therefore you should arrange a larger space for me where I could live happily."
King Styavrat removed the fish from the kamandalu and placed her in a large pitcher. But in a few moments her size grew so large that the pitcher too turned small for her. She said to Satyavrat again, “King! This place too is very small for me. Therefore please put me in a large water pond so that I could live there happily."
King Styavrat transferred the fish into a large pond. But her size grew so large in a few moments that even the pond turned small for her. Then she pleaded again, "Hey king! This pond too is very small for me. Therefore put me in a larger water reservoir so that I could live there happily."
The fish was growing so fast in size that Satyvrat was amazed with the phenomenon. But, without a word, he brought her out of the pond and transferred her into the sea. Entering the sea, the fish acquired the size of a huge fish and came to Satyavrat and said, "King! You had promised to protect me, why then have left me amid these violent water cratures? Do not leave me here."
Ashamed King Satyavrat spoke then, " Hey huge fish! I am a dimwit who, despite being aware that the entire universe is created by Lord Vishnu, who is its fosterer, protector, and destroyer, resolved to give you shelter out of ego. Nothing is possible in this universe without the wish of Lord Vishnu. God! Who are you to have granted me wisdom in the fish incarnate, which grew so large in size in a matter of few moments? I have neither seen nor have heard of a water borne creature with such a divine capability. Certainly you are the omnipotent Lord Narayan. You incarnate time to time only to bless devotees. Although all of your avatars are meant to benefit the human being, yet I am curious to know the purpose of your this avatar of fish."
Then the fish incarnate of Lord Vishnu spoke being pleased, "Hey Satyavrat! The time for annihilation has arrived. All the loks including bhulok (earth) will drown in the sea of annihilation on the seventh day from today. A large boat will come to you at that time. Taking the subtle bodies of all the jeevs of the earth, and the seeds of small and big grain etc. you board that large boat along with saptrishis. When the boat will start shaking due to violent blow of storm, I will come there appearing in this fish form and you would tie the boat through Vasuki snake with my fin. After that I will float in the sea pulling the boat till the end of annihilation."
Saying this Lord Matsya disappeared and Satyavrat began waiting eagerly for the annihilation.
Right on the seventh day, clouds began raining horrificly and the water of the sea started rising breaking past the shores. In a matter of time, the entire earth submerged under the water. A boat came there at that point of time. He boarded the boat with the subtle bodies of all the species, and seeds of grains etc. along with saptrishis,. When the boat started shaking due to terrific tides of the sea, Satyavrat started remembering Lord Vishnu. At that time, Lord Vishnu appeared in matsya form. Satyavrat tied that boat through Vasuki snake with the large fin of the Lord Matsya and prayed him to provide the divine wisdom. Then, floating with the boat in the sea, Lord Vishnu gave discourse to Satyavrat of the entire divine Puran full of knowledge, devotion, and karmyog. The discourse that Lord Vishnu, in the fish form, delivered to Satyvrat during this time period is called Matsya Puran. Later, by the blessing of Lord Vishnu, Satyavrat was born in the house of Lord Sun and consecrated by the designation of Vaivaswat Manu.