Among the Lord’s incarnations taken at various times for protection of the good and for destruction of evil and for establishment of dharma, the incarnation as Matsya, fish, is considered the first. The highlight of this incarnation is the Lord’s valuable instruction on the highest wisdom that helps one to attain liberation, pointed out Sri B. Damodhara Dikshitar in a discourse. The Bhagavata Purana states that this avatar takes place at the close of Brahma kalpa, when the earth and other regions are engulfed by the seas owing to a great deluge. Brahma is in deep sleep state and a powerful asura named Hayagriva carries away the Vedas.
At that time a famous and devout king Satyavrata is performing penance in water. He finds a tiny fish in the water he has collected in his hands for offering ‘argya.’ The fish wants to be protected and he puts it in his jar of water. The fish keeps growing in size and the king places it in suitable containers until it becomes so huge that he has to put it back into the sea. He soon realises that the fish could be none other the Lord. The Lord reveals His identity and explains that soon there would be a Pralaya and that the king should collect herbs, plants, seeds, typical animals, etc, and along with the Sapta rishis get into a ship that will be sent to him. In the darkness, the Lord would appear as fish to guide and steer the ship through the Pralaya waters until Brahma’s night gets over.
As promised, as the Lord tugs the ship and protects them throughout the period of deluge, He imparts spiritual wisdom. When the Pralaya ends the Lord restores the Vedas to Brahma, who is now awake. Satyavrata, endowed with knowledge and experience of Truth, is graced to become the seventh Manu, Vaivaswata, in the present kalpa.