It is âgavataPurâa Kâlpic revolution. Vasûki sustains the earth and its inhabitants for one Kâlpic period. The thousand hoods represent the thousand Maha yugas of every Kalpa. The Asuras held the mouth end of the serpent king and the Devas held the tail end. And the Devas acted wisely. For as the Kalpa waned, they got the supremacy.
The tortoise thrusts out its limbs and draws them in. Man is drawn outside by his senses during material descent and he is drawn in by his spiritual ascent. It is by the power of discrimination when fully developed that a man returns to his higher nature.
Srî or Lakshmî is the divine energy of Vishnu. She is the Energy of preservation, of evolution and progress She works out all that is good, all that is beautiful, and all that is powerful in this Universe. The possibilities of purely material development or of Nature's own evolution, are limited, and they are worked out in time. Then there is a void. There was this void in our universe and Trilokî become deprived of Sri. This was the curse of Durvasas, an Avatâra of Siva.
The Churning took place as a remedy for this evil. Fresh forces had to be brought into requisition, fresh elements that could secure the spiritual evolution of the universe. Lakshmî herself reappeared in a most enchanting form, as the energy of a new evolution, the very best that man was capable of. The necessaries of this evolution also appeared and became powers in the hands of those that had to take part in the spiritual evolution of the universe.
All evolution is preceded by dissolution. Unless we give up the evil element in us, we can not acquire the good. The evil has to be destroyed and the Lord of destruction, in his infinite compassion, accepted this poison for himself, to do away with the evils of the Universe.
The Poison only opens the door for Amrita, the spiritual nectar. The famous Purusha Sukta says: -- "He placed Amrita or eternal bliss in the higher three Lokas." The Bhâgavata renders this famous saying into the eighteenth sloka of the 6th. chapter of the Second Skandha. Commenting on this sloka, Sridhara says, bliss in our Trilokî is only transitory and the dwellers of Mahar Loka have also to leave their abode for the higher Jana Loka, when they are oppressed by the fire of Kâlpic dissolution. Amrita was secured to the higher Lokas, as there is no selfishness in them. (III. 10-9.) Could the Asuras, the gods of selfishness, aspire to have life immortal and unlimited bliss. Vishnu decided otherwise.