Mahapralaya and Vishnu's Origin

Brahma said

Brahmana, best of the understanding, you have asked a virtuous question. You have always cared for the welfare of the worlds, and this will do them good; when all the worlds hear it, their sins will be destroyed. So I will tell you of Shiva's tattva, which never decays. Neither I nor Vishnu truly know it, nor his supreme form, nor does anyone else. At the great dissolution all that moves and stays is destroyed and everything is covered in darkness. There are no suns, planets or stars, no moon, no night or day, no fire, wind, earth or water, no Pradhana. All is empty and without energy. Nothing can be seen, nothing described as sound or touch, nothing manifest as smell or form. There is no taste, no direction. The only truth is a darkness no needle could pierce. All that exists is what the texts call "the cause, the brahman." In that state nothing can be called existent or non-existent. Yogis perceive it constantly in the space inside themselves. The mind cannot grasp it and words cannot express it. It has no name, shape or colour; it is neither thick nor thin, tall nor short; lightness and heaviness do not apply; it neither grows nor shrinks. The texts say it at once envelops everything. It is truth, knowledge, the infinite, supreme bliss, splendid, immeasurable, without support, changeless, formless and without qualities. Yogis can approach it. It fills everything and alone is the cause. It is beyond doubt, beginningless, free of maya and hardship, without a second, without beginning or end, without growth, pure consciousness. Since it had no alternative, it could be neither named nor left unnamed. After a time it decided to have a second. Having no form itself, it chose in play to make an alternative with form. This was auspicious and held every quality of power and every kind of knowledge. It could go everywhere, take every form, see everything, was the cause of everything, deserved the worship of all, was the beginning of all and constantly purifies all. So it conceived this manifest form of Ishvara, pure in nature. The original is without second, beginning or end, lights everything, and is consciousness itself. This is the supreme undecaying brahman, which goes everywhere and has no form. Having made the second, with a manifest form, it vanished. That manifest form is Sadashiva, whom the learned of old and now have called Ishvara.

From his own portion, by his own wish and play, Ishvara made Shakti. She came from his body without harming it. She does not change, and has several names: Pradhana, Prakriti, Maya, Gunavati, Paraa and mother of the Buddhi tattva. She is called Ambika, Prakriti and Ishvari, mother of the three gods and the first cause. The auspicious one has eight arms and a wonderful face, glowing as though with a thousand full moons, adorned with many ornaments, moving in many ways. Devi bears many weapons and her eyes are like full lotuses. Her energy is beyond imagining; she is the womb of all. This Maya is one, yet unites in many ways. The supreme Purusha is Ishvara, Shiva or Shambhu, and nothing is above him. The Mandakini rests on his head; he has three eyes, the moon on his brow, five faces, a gentle self and ten arms with a trident, fair and pure as camphor, his body smeared with ash. The brahman took the form called Kala and, with Shakti, made the field called Shivaloka. This is the supreme field Kashika, shining above all, called the place that gives the highest nirvana. In that lovely field the two, as supreme bliss and in supreme bliss, played. Sage, even in the dissolution that field is never without Shiva and Shivaa, so it is called Avimukta. The wielder of the Pinaka first named it Anandavana because the field gives bliss; Avimukta came later. Shiva and Shivaa played in Anandavana.

Divine rishi, then they wished another being to be made. Shiva thought: "Let him carry this great burden. We will stay in Kashi and only give nirvana. By my grace he will create, protect and dissolve. When he exists, we can enjoy Anandavana with our joy undisturbed by anything outside." With Shakti, Lord Parameshvara churned the ocean of his thoughts and gathered the jewel of sattva, the coral of rajas and the crocodile of tamas. From a tenth part on the left of his ocean of nectar he made a being, the loveliest in the three worlds. Since sattva was in excess, this being was calm and deep like the sea. Sage, he was patient and had no equal. He was the colour of blue sapphire, glorious, lotus-eyed, golden in form, in two fine garments, radiant, with arms like staffs, unconquerable. That being bowed to Shambhu Parameshvara and said, "Lord, give me a name and a task." Hearing him, Shankara Mahesha smiled and spoke in a voice like thunder.

Shiva said

Because you pervade everything, you will be called Vishnu; because you will give happiness to your devotees, you will have many more names. Stay steady and do austerity, so that the supreme task may be done.

Brahma continued

With that, he breathed the nigama texts into him. Achyuta bowed to Shiva and began long austerities. With Shakti and his companions, Parameshvara vanished. Achyuta tormented himself for twelve thousand divine years but could not see the Lord he wanted, who is always good to behold. Doubt came to Vishnu. He thought lovingly of Shiva, remembered him in his heart and asked, "What now?" Then Shiva's auspicious voice came: "A doubt has arisen, so do austerity again." Brahmana, hearing it he did terrible austerity for a long time on the path of meditation. By that path understanding arose in the being called Vishnu. Amazed and glad, he wondered, "What is truly great?" Through Shiva's maya and his own effort, many streams of water began to flow from Vishnu's limbs. Great sage, they covered everything in that vast void. This water has the form of the brahman, and touching it destroys sins. The being Vishnu, tired, slept on that water, supremely happy, for a long time in that deluded state. So, in keeping with the shrutis, he gained the name Narayana. Except for that Purusha, nothing else then existed in nature. Meanwhile other tattvas came forth from the great-souled one. Wise one, hear them. Mahat came from Prakriti. From Mahat the three gunas; from differences among the gunas three kinds of ego; then the tanmatras and the five gross elements; then the organs of action and perception. Supreme among rishis, I will give the number: all that comes from Prakriti is insentient, but Purusha is not. Together they are twenty-four tattvas. At Shiva's command he accepted them and went on sleeping in what was a form of the brahman.