Narasimha Purana is one of the 18 Upa Puranas written by Srila Vyasadeva , Upa Purana just means that it does not cover the 10 subjects of the Mahapuranas , but 5 or more.This has been explained by Sukadeva Goswami in the 12 Canto chapter 7:
O brāhmaṇa, authorities on the matter understand a Purāṇa to contain ten characteristic topics: the creation of this universe, the subsequent creation of worlds and beings, the maintenance of all living beings, their sustenance, the rule of various Manus, the dynasties of great kings, the activities of such kings, annihilation, motivation and the supreme shelter. Other scholars state that the great Purāṇas deal with these ten topics, while lesser Purāṇas may deal with five.
chapter:40 Hirnayakasipu takes over the heavenly planets and kicks out the demigods. After wandering the earth for long time(disguised as ordinary human beings) the demigods talk with Brhaspati that confirms that he and other sages are predicting that soon Hiranyakasipu will be finished, and tells them to go to the ocean of milk , and headed by Lord Siva they go there and and chant many names of Visnu to Lord Visnu and being pleased He asks what they desire.And they answer that He being all knowing also knows this answer, so why is He asking them /Lord Visnu smiling answers that He is pleased they chanted 100 of His Holy names , and tells them not to worry , and tells Lord Siva that he can go back to Kailash and that soon Sri Prahlada Maharaja will appear, and when Hiranyaksipu later tries to kill him, He, Lord Visnu will appear and kill Hiranyakasipu. chapter 41: Lord Brahma tells Narada Muni that Hiranyakasipu is doing Tapasya at Kailash and ask him what he suggest to do, Narada Muni tells him not to worrry as Lord Visnu has shown him a "few tricks", he goes there then Narada Muni and Parvata Muni assumes the form of birds and starts to chant the name of Lord Visnu and it aggrevates Hiranyakasipu so much that he tried to kill the birds and simply gives up his penance there. Coming back to his wife she is very happy and she asks him why he has finished his tapasya so early: She did not expect him for the next 1000 celestial years, Hiranyakasipu explains the birds was chanting:Om namo Narayanaya namah " and disturbing his meditation and as he states this he impregnates his wife while chanting " Om namo Narayanaya namah. Kayadhu becomes pregnant with Prahlada. and then an interesting statement is there: Just as devotion to Lord Hari increases more and more even in the harsh Kali yuga the devotion of Prahlada as he grew up increased daily. Then it is explained that Prahlada one days meets his demoniac father and Prahlada starts glorifying the name of Krsna, and Hiranyakasipu temporarily controls his angers and tells him that chanting Krsna's name is not allowed all over the universe under his rule. And Prahlada tells him this is a great sin and he should immediately start chanting, this infuriates Hiranyakasipu and he tells Prahlada to leave his palace at once and calls for the teacher being brought to him in chains. He chastises the teacher who is a Vishnu bhakta and instructs the teacher to worship him instead, .chastises Prahlada for not being obedient to he who is both his father and ruler of the universe and glorifying "the enemy of the asuras Visnu".The teacher leaves and it stated from then on he starts worship of Hiranyakasipu simply to fill his belly chapter 42 In this chapter Prahlada Maharaja goes to his teacher, after he comes back Hiranyakasipu questions him, and Prahlada glorified Lord Visnu and states no other subject is worthy of discussion, this infuriated Hiranyakasipu once more that then orders to have Prahlada killed and the soldiers rush at him with weapons that simply turn around and harm them, then Hiranyakasipu calls for snake charmers that bring the most powerful snakes in the universe to attack Prahlada,who again is fully absorbed in Lord Visnu and the fangs of the snakes are broken and they are all bleeding, and not even the skin of Prahlada is harmed. The snake charmers explain to Hiranayakasipu these snakes normally could even melt stones with their fire of poison . Sanda and Amarka asks Hiranyakasipu to allow them to bring Prahlada to their ashram to teach him in the demoniac principles, and Hiranyakasipu agrees .
chapter 43 : In this chapter it is been explained that the class mates of Prahlada Maharaja asked him why he was always so happy and detached from world affairs. Prahlada Maharaja replied that he happy due to his devotion to Lord Visnu and pointed out the futility in the temporary happiness of wealth ,followers and admirers and a beautiful wife.He reminded them of the souls suffering in the womb .He stated:"O sons of the Asuras ,when this world is always full of anxiety ,how then can a real scholar enjoy it? Prahlada Maharaja pointed out that no other shelter than the Lotus feet of Krsna has any value in this world .He says that people of this world is so attached to this fleshy body full of bacteria's and urine ,He pointed out that worship of Lord Visnu is not simply done with opulent items ,but that one should chant the holy names of Krsna with devotion as it will please the Supreme Lord .One must always realize the miseries of the material world and fully engaged in chanting Krsnas holy names eventually give up ones body.That this is the Supreme remedy of this material world. Prahlada Maharaja said:" Give up all worldly passions and meditate on Sri Krsna situated in the heart .Adore Lord Mukunda situated in your heart along with His divine weapons Conch ,Disc ,Lotus and club ,I know you are not atheists and thus I am explaining to you that Lord Visnu is in the heart of all living beings and is eternally Their dearmost friend and wellwisher .The sons of the Demons (Daityas) asked Prahlada Maharaja: O learned Prahlada ,since childhood you only had Sanda and Amarka as your teachers so how did you develop your Krsna consciousness ? Prahlada Maharaja answered: When my father Hiryanakasipu did tapasya , Indra lured my mother away with magical and mystic powers with the idea to satisfy his passion, he was stopped by Sri Narada Muni that severly chastised him: "Oh greatest of fools ,leave this chaste lady alone ,the baby in her womb is the greatest of Lord Visnus devotees .Indra bowed his head at the feet of my mother and left for Indra loka. Narada Muni took my mother to his asrama and gave her transcendental knowledge .O sons of the daityas ,the practice in childhood .the grace of Lord Visnu ,and this Krsna consciousness have been given to me by Srila Narada Muni . I have never lost this treasure
One day Hiranyakasipu
was strolling around the city of Ahovalam in the night concealing his identity,
He noticed that someone was chanting the name of Lord Ramachandra.It was his son Prahlada Maharaja .He called his demoniac ministers and advised them that when Prahlada would fall asleep they should have him tied with Nagapasa (ropes made of live snakes) andthen throw him into the ocean.They thought Prahlada was asleep but he was in deep meditation on Lord Visnu using the quiet nighttime for his meditation (dhyana yoga).They took him to the ocean at Viskahpatnam and threw him in the ocean and threw part of the mountain at Simhacalam on top of him .(thus thinking if he would not die from the fall and drown he surely would be killed by the mountain boulders The ocean personified , placed Prahlada Maharaja on the shore and offered him many gifts of several gems, and
Lord Garuda came and ate the snakes that was used for the Nagapasa .The ocean personified bowed before Prahlada Maharaja and offered a prayer: " O devotee Prahlada ,performer of great deeds, please open your eyes and make me holy by your grace.This brought Prahlada back to external consciousness, and broke his meditation on Lord Visnu .He asked Sri Varunadeva how he had come there. Sri Varuna told him of the reason he had entered the ocean caused by his demoniac father.After Varuna left Lord Visnu appeared and took Prahlada on his lap.( The Narasimha Purana states Lord Visnu appeared to him ,whereas the Stahla Purana at Simhacalam explains the Lord appeared as Lord Varaha Narasimha half Lord Varaha and half Lord Narasimha ) Lord Visnu told Prahlada that shortly he would again appear to him as Lord Narasimha when he would kill his demoniac father.Then Lord Visnu disappeared and Prahlada Maharaja cried in separation from his beloved Lord.
After the demons (asuras) realized that Sri Prahlada Maharaja was not killed by throwing him in the ocean from the mountain of Simhacalam ,they reported it to Hiranyakasipu who demanded Prahlada be brought before him. Prahlada greeted his father from a distance with folded hands .Hiranyakasipu challenged Prahlada that his Lord Visnu should come and protect him ,and he pulled out his sword Candrahasa. Where is your Lord Visnu if you state He is omnipresent, then let Him manifest from this pillar in my palace to protect you ,otherwise if your words are false I will divide you in two parts with this sword .( note the Chandrahasa is a sword that belongs to Lord Siva ,how Hiranyakasipu obtained it , can only have been from pleasing Lord Siva by tapasya, Ravana also obtained this sword from Lord Siva when he once tried to cross Kailash mountains but was ordered to go around by Sri Nandi, Lord Sivas bull carrier teased him and Nandi cursed him that one day his kingdom in Sri Lanka would be destroyed by monkeys , Ravana then tried to lift the Kailash mountain , and Lord Siva made the mountain very heavey so Ravanas fingers got trapped under the mountain , he then offered prayers to Lord Siva called Siva tandava stotra, Lord Siva being pleased gave Ravana the Candrahasa sword and told him if he misused it ,it would be his end Chandrahasa- means the smile of the moon)
Sri Prahlada saw Lord Narasimha in the pillar and when Hiranyakasipu broke the pillar with the sword of Lord Siva , Lord Narasimha emerged from the pillar ,His eyes where very large ,He had a gigantic mouth , large jaw, and long arms , His nails and feet where very large ,His mouth was glowing like the fire of Kala (time) .His jaw spread to His ears and He looked dreadful.Thus the Supreme Lord Visnu emerged from the pillar and started roaring with a loud voice, the soldiers of Hiranyakasipu attacked Lord Narasimha with arrows and other weapons , Lord Narasimha destroyed the auditorium of Hiranyakasipu and killed the army within moments.Lord Narasimha roared so loudly that all directions shivered
Hiranyakasipu send another army of 85.000 soldiers they where killed by Lord Narasimha in moments .Lord Narasimha then destroyed another part of Hiranyakasipus large palace .Hiranyakasipu ordered a third army to attack and catch Lord Narasimha and kill the Lord.This army was also killed .Lord Narasimha killed millions of soldiers send by Hiranyakasipu ,when the sun started setting Lord Narasimha caught Hiranyakasipu and suppressed his armor and strength and mystic powers , Lord Narasimha took Hiranyakasipu into the doorway , and started piercing the body of Hiranyakasipu while keeping him on His thighs.
Hiranyakasipu desperately said:" My chest that is now being pierced by Narasimha at this moment is the same chest on which the tusks of Airavata broke (the elephant of Indra) and even a blow of Lord Sivas axe was in vain"
As Hiranyakasipu finished these words , Lord Narasimha shattered the heart of Hiranyakasipu , it was done the same way an elephant splits the lotus plant, his body ripped in two parts ,due to the crushing power of Lord Narasimha the body of Hiranyakasipu turned into dust .This sight made Lord Narasimha laugh. Lord Brahma and all the demigods showered flowers on the transcendental body of Lord Narasimha .Lord Brahma on the instruction of Lord Narasimha made Prahlada the king of the demon race. Lord Narasimha reinstated Indra as the king of the heavenly planets in the presence of all the demigods. Lord Narasimha went to Sri Sailam and was worshipped there by all the demigods to permanently safeguard the interests of the devotees and punish the wicked .All beings in the universe became devoted to Lord Narasimha. Anyone who listens to this pastime of Lord Narasimha or reads it becomes free from all evils in his life. Whether male or female ,whosoever listens to this supremely auspicious lila of Lord Narasimha gets rid of all faults of associating with demoniac persons, free from sorrow ,mourning and agony and from the pain of being a widow .Even the demoniac. the evil doers, and those whose children who are evil ,and those who imitate the activities of evil persons. those who have no faith in religion and those attached to sensual activities all become holy at heart by listening to these pastimes of Lord Narasimha.Lord Narasimha the monarch of all monarchs ,took this fearsome form to kill the demoniac Hiranyakasipu and all his followers.