Eighteen Puranas mention the Narasimha avatara. To be rid of one's sins, one goes to Prayag, Gaya and Kasi. But all this is not needed, if one goes to Ahobilam, abode of Lord Narasimha, said Kidambi Narayanan. A day in Ahobilam is equal to many years of visit to other places. Donating 1,000 cows, with gold tipped horns in Kurukshetra, is supposed to confer good on a person.
But listening to the story of Narasimha on a full moon day or a new moon day is superior to this. When Lord Srinivasa and Padmavathy marry in Tirupati, the Lord asks Brahma to worship Lord Narasimha at the Ahobilam shrine before the divine wedding. Ahobilam is considered superior to a 1,000 yuga sojourn in Varanasi.
Among the Puranas, the Vishnu Purana is considered the most important. In this purana, Maitreya asks Parasara to tell him about Lord Narasimha.
A Vaishnavite Acharya observed that on three occasions the Lord's quickness to respond to His devotees was challenged, and in each case, He proved Himself to be quick to help them. When Gajendra's foot was caught in the jaws of a crocodile and the elephant cried out to the Lord, He came in a dashing hurry on His mount Garuda, and using His discus killed the crocodile.
Again when Draupadi's sari was yanked in the Kaurava court, while her husbands and everyone else watched in silence, she called out to Lord Krishna. The Lord instantly responded by sending yards and yards of dress, so that the Kaurava prince kept pulling and unravelling, but the job never seemed to get done. He gave up in exhaustion. Here too, if the Lord had not responded in the nick of time, Draupadi would have been shamed in the presence of many. But the Lord's help was readily available.
In the case of Prahlada, the child told his father that the Lord was everywhere, including in the pillars of his father's palace. Hiranyakasipu prepared to strike a pillar. There was no knowing which pillar he would strike. And yet the Lord was keen that the child's words should not be proved false. So He was present in every pillar, so that whichever pillar the asura struck, He would be there.