Srimad Bhagvata Mahapurana: Book 6: Chapter 9: Verses 15-27
gave a loud roar and shook the earth with (the stamp of) his feet. Terribly afraid (of him), all created beings ran to and fro (in all directions) as they saw him respiring again and again with his extensive gaping mouth, containing fearful teeth and deep as a cavern, which seemed to imbibe the firmament, lick the stars with the tongue and devour (all) the three worlds. That (apparently) sinful and most ferocious demon was rightly named as Vrtra inasmuch as (all) these worlds were enveloped by that (gigantic mass of) darkness appearing in the form of Twasta's offspring.Rushing against him with their troops, the generals of the gods assailed him, each with his hosts of celestial missiles and weapons; he (however) swallowed them all. With their splendour eclipsed (his) nay, amazed and dejected (at their discomfiture), they all thereupon composed themselves and (mentally) approached Lord Narayana (the most ancient Person), dwelling in their very heart (with the following prayer).
The gods prayed : May our safety follow from Him (the Supreme Person), of whom is afraid (even) the well-known Death (the Time-Spirit)-Death, to whom (the five elements, viz.,) ether, air, fire, water and earth, the three worlds (heaven, earth and the intermediate region, including their inhabitants, the creation of the five elements), nay, Brahma and others (the rulers of these worlds) and we (gods, who owe our allegiance to these), all pay tribute (homage), trembling (with fear). An ignoramus is he who resorts (for protection) to anyone else than the aforesaid Lord-who is (ever) free from egotism, who is perfectly tranquil (free from likes and dislikes), who has all His desires fully satisfied by the (very) realization of His own (blissful) Self and who is (ever) uniform (unconditioned)-in that he desires to cross the ocean with the help of a dog's tail. The same Lord in the form of the divine Fish--to whose colossal horn king Satyavrata (destined to be the seventh Manu) fastened his boat, which was no other than the earth, and duly got through the peril (in the form of the Deluge)_ will surely protect even His dependants, against the danger from (the demon) Vrtra, which is (so) difficult to get rid of. At the dawn of creation Brahma (all but) fell from the lotus (sprung from the navel of the Lord) on the water that had submerged everything during the period of universal dissolution and which had assumed a frightful aspect due to the roaring of its billows raised by the fierce winds. May the same Lord be our saviour, with whose help (by whose grace) the same Brahma-who was all by himself-got over that peril. That (supreme) Lord, though (all) alone, evolved us (gods) by His own Maya (creative energy); and with His help (by His energy and guidance) we (are enabled to) create the universe already created by Him. Yet, regarding ourselves as independent rulers, we are unable to behold His form although He has been fully active even prior to us (as our inner Controller and Director and the actual Creator of the universe). Though ever existent, yet manifesting Himself through (various) forms among the gods, Rsis (seers), human beings and lower animals by His own Maya (divine will), He protects us in every Yuga and (sometimes) even more than once in a Yuga, treating us as His own, when He finds us excessively tormented by enemies. We all resort for protection solely to that Shining One, our object of adoration, and (final) Cause manifested in the form of the universe and yet transcending it, appearing (both) as matter and spirit, and affording protection to all. That Supreme Spirit will bring happiness to us, His devotees.