Srimad Bhagvata Mahapurana: Book 8: Chapter 17: Verses 14-28
The Lord manifests Himself before Aditi and grants her desired boon
(Nay,) you long to approach and behold (with your own eyes)the sorrowful and bewailing wives of your enemies when the latter have been slain by your sons, the eldest of whom is Indra. You (further) desire to see your sons highly prosperous, with their glory and splendour restored and diverting themselves after regaining mastery over heaven. Those Asura generals are for the most part invincible at present ; that is My conviction, 0 celestial lady! For, they are protected by Brahmafas to whom (the all-powerful) Time is propitious. (Hence) heroic valour against them will not yield happiness. Nevertheless, O heavenly lady, some expedient must be thought of by Me, propitiated by your observance of a sacred vow. (For) My worship ought not to prove fruitless, bringing as it does its reward according to the desire of the worshipper. Worshipped in the proper way for the protection of your sons through (the observance of the vow called) Payovrata and duly extolled by you, I shall assume the role of a son to you, entering by a part of My Being the procreative energy of the sage Kasyapa (son of Marici), and protect your progeny.
(Therefore,) seek your consort, the faultless Kasyapa (a lord of created beings), O blessed lady, visualizing Me as present in this (very) form (standing before you) in the person of your husband. This (secret) should on no account be disclosed to another by you, even when questioned. (For) all secret plans of the gods, 0 celestial lady, succeed (only) when scrupulously guarded. Sri Suka went on: Saying this much, the Lord disappeared on that very spot. Having secured the rare boon of Lord Sri Hari's birth through her, Aditi waited upon her husband with supreme devotion like one who has accomplished her purpose. By power of concentration the said Kasyapa of true insight actually perceived a part of Sri Hari having entered his mind. Having (fully) concentrated his mind, O Pariksit, the sage Kasyapa (who was alike to the gods and the Asuras) placed (mentally) in Aditi his seed long conserved through asceticism (even) as the wind (which equally pervades everywhere) places (a spark of) fire in firewood. Perceiving the eternal Lord having entered the womb of Aditi, Hiranyagarbha (Brahma) proceeded to praise Him with mysterious epithets (as follows).
Brahma prayed : May You triumph, 0 Lord hymned by many I Let my salutation be to You, O Lord of might‘)' valour !! My greetings to the Lord who is friendly to the Brahmanas I Hail, hail to the Controller of the three Gunas (modes of Prakrti)!! O Salutations to You, the Maker (of all), who were born of Prtni (the previous incarnation of Aditi) and are revealed in the Vedas, who hold the three worlds (earth, heaven and the middle region) in Your navel, and (at the same time) stand above the three worlds; (nay,) who have entered all embodied beings as their Inner Controller and are all-pervading. You, whom the Vadas refer to as the supreme Person of unlimited powers, are the beginning, end and middle of the universe. As the Time-Spirit, O Lord, You draw the universe (after You) even as a deep stream draws (after it) whatever has fallen into it.Indeed You are the Creator of (all) created beings, (both) immobile (inanimate) and mobile (animate), as well as of the lords of creation. (Hence) You are the supreme refuge, O Lord, of heavenly beings (lit., the denizens of heaven) fallen from heaven, even as a boat is for one about to be drowned in water.
Thus ends the seventeenth discourse, hinging on the story of the descent of
Lord Vamana, in Book Eight of the great and glorious Bhagavata-Purana, otherwise known as the Paramahamsa-Samhita.