Pralaya-payodhi-jale dhṛtavān asi vedam. This is a song sung by great Vaiṣṇava poet Jayadeva Gosvāmī. The purport is that when there was devastation, the whole universe was flooded with water. The ultimate dissolution of this material world will be, first of all, there will be no water, all water on the earth will be dried up by scorching heat of the sun. The sun will become twelve times stronger as it is at the present moment. In that way, evaporate all the waters, the seas and the oceans will be all evaporated. Therefore all living creatures on the Earth will die, and then, due to scorching heat, practically everything will be turned into ashes. Then there will be rain for a hundred years, torrents of rain, like the trunk of the elephant, and thus the whole universe will be filled with water. That is called pralaya-payodhi. At the time of devastation, pralaya, the whole universe will be Just like it is now filled with air, at that time it will be filled up with water.
So at that time Vedas will be saved by the Lord on a boat, and the boat will be stuck up in the wings of the great fish. That great fish is the incarnation of Kṛṣṇa. Therefore he is worshiping, keśava dhṛta-mīna-śarīra jaya jagadīśa. So mīna-śarīra. The next is kṣitir iha vipulatare tiṣṭhati tava pṛṣṭhe dharaṇi-dhāraṇa-kiṇa-cakra-gariṣṭhe. So there will be churning, next incarnation is tortoise. On the back of the tortoise the meru-parvata will be fixed up, or the world will rest on the back of the tortoise. This is second incarnation. First fish, and then tortoise.
Then varāha-avatāra. One demon, Hiraṇya, Hiraṇyakaśipu and Hiraṇyākṣa. So he'll, by his demonic activities will throw the Earth on the Garbho Sea. There is a sea within this universe. Half of the globe is filled up with Garbhosamudra, on which Garbhodakaśāyī Viṣṇu is there, and from Him a lotus stem comes out wherein Brahmā takes birth. So all the planets are hanging as different stems of this original stem coming out from the abdomen of Garbhodakaśāyī Viṣṇu. So one demon of the name Hiraṇyākṣa, he will put this Earth within this water, and at that time, the Lord will come out in the incarnation of Varāha. The Varāha incarnation came as a small insect from the nose of Brahmā, and when he put it on his hand, He began to increase. In this way He assumed a very gigantic body, and with His tusk, He picked up the Earth from within the water of Garbho ocean. That is called keśava-dhṛta-varāha-rūpa.
The next is tava kara-kamala-vare nakham adbhuta-sṛṅgaṁ dalita-hiraṇyakaśipu-tanu-bhṛṅgam. Hiraṇyakaśipu, he was another demon who wanted to be immortal. So he took benediction from Brahmā that he'll not die on land, in the sky or in the water. So, in order to keep as it is, the benediction given by Brahmā, Lord Kṛṣṇa tries to honor the words of His devotee. So Brahmā gave him benediction, "Yes, you will not die on land, on water, in sky." But Nṛsiṁha-deva appeared as half-lion, half-man, because Hiraṇyakaśipu also took benediction from Brahmā that he'll not be killed by any man or any animal. So He assumed the form of something which you cannot say a man or animal, and He put the demon on His lap, which is neither land, water or sky. And he wanted to, not to be killed by any weapons. Therefore the Lord killed Him with His nails. Nail is not considered as weapon. In this way, he (Hiraṇyakaśipu) wanted to cheat Brahmā, but the Lord is so intelligent that He cheated Hiraṇyakaśipu, and killed him. Keśava dhṛta-narahari-rūpa. Dalita-hiraṇyakaśipu -tanu -bhṛṅgam. Just like with our nails, we can kill any insect. Take an ant, you can bifurcate it. Similarly, Hiraṇyakaśipu was such a giant demon, he was compared just like a little insect, and was killed by the nails of the Lord.