In the Vishnu Purana, we are introduced to the story of Prahalad. We are told he is the son of an asura king, Hiranyakashipu. Because Hiranyakashipu receives a boon from Brahma, he cannot be killed by any human or animal, either inside or outside a dwelling, at day or at night. Therefore, he gains a certain immortality and starts demanding everybody worship him as God.

However, Prahalad refuses to accept his father as God, and keeps worshipping Vishnu or Narayan, and keeps saying Narayan is present everywhere, in day and night, within and without. Prahalad prefers to worship only Vishnu, chanting his name all the time.