Srimad Bhagvata Mahapurana: Book 7: Chapter 7: Verses 1-16
(Prahrada's) teaching to the Daityas' sons
Narada resumed : Questioned thus by the Daityas' sons, the Asura (Prahrada), that great devotee of the Lord, smilingly addressed them (as follows), calling to mind my teaching (to him). Prahrada began : Our father (Hiranyakasipu) having left for Mount Mandara to practise austerities (and having been eaten away by white ants), Indra and the other gods launched a great military campaign against the Danavas, saying: "Fortunately (for us) the evil one (Hiranyakasipu), the scourge of the world, has been eaten away by his own sin as a serpent by ants." Perceiving their mighty undertaking and being struck by the gods, the terror-stricken Asura generals, who were all anxious to save their life, hastily fled in every direction, paying no heed to their wife and children, friends and relations, houses, animals and other household goods. Desirous of victory, the gods looted the king's residence; while Indra (the ruler of the gods) even seized the queen, my mother. Narada (the celestial sage), who came there by chance, saw her being taken on the road, trembling with fear and crying like a female osprey. He peremptorily said, "You should not take this innocent lady, O lord of divinities ! Leave, leave, O blessed one, the good woman, who is another's wedded wife."
Indra replied : There is in her womb (in the form of an embryo) the formidable seed of Hiranyakasipu (the enemy of the gods). Let her (therefore) stay (in my captivity) till (the time of) delivery. I shall let her go when I have achieved my object (by killing the new-born babe).
Narada said : He (the child in her womb) is not only (absolutely) sinless but a great devotee of the Lord and eminent by his own qualities. This mighty servant of Lord Visnu will not meet his death at your hands. Thus addressed (by Narada) and accepting the advice of the celestial sage, Indra left her (my mother) and going round her (as a mark of respect) out of devotion to me (the beloved of the eternal Lord), returned to heaven. Then the sage took our mother with due honour to his own hermitage and, comforting her, said, "Stay here, my daughter, till the return of your husband." She too signified her assent in the words "So be it !" and lived near the celestial sage, free from all fear, so long as my father (the ruler of the Daityas) did not cease from his terrible austerities. For the well-being of her embryo (myself) and in order to deliver it at the desired moment (after the return of her husband) the virtuous and pregnant lady waited upon the sage in that hermitage with supreme devotion. In order to assuage her grief and for my sake too the compassionate and powerful sage imparted (to her instruction in) both the essence of religion (in the shape of Devotion to the lord) and pure wisdom (discrimination between the Self and non-Self). That teaching, however, disappeared from the mind of my mother due to (the inordinate) length of time (that has since elapsed) and because of her womanly nature. Its memory has not (however) left me, the favoured of the sage, even to this moment.