The Katha of the appearance of Lord Nrsimhadeva from the 7th canto Srimad Bhagavatam: - The powerful asura (demon) Hiranyakashipu the king of the demons, his brother, another demon Hiranyaksha who had been creating lots of disturbances, had been killed by Lord Varaha, an incarnation of Lord Krsna. Hiranyakashipu also was creating disturbances by harassing the sages and the devas. Hiranyakashipu wanted to get revenge upon Lord Vishnu for the killing of his brother so he performed severe austerities:

"Seeing Hiranyakashipu engaged in this austerity, the devas returned to their respective homes, but while Hiranyakashipu was thus engaged, a kind of fire began blazing from his head, disturbing the entire universe and its inhabitants, including the birds, beasts and devas. When all the higher and lower planets became too hot to live on, the devas, being disturbed, left their abodes in the higher planets and went to see Lord Brahma, praying to him that he curtail this unnecessary heat. The devas disclosed to Lord Brahma Hiranyakashipu’s ambition to become immortal, overcoming his short duration of life, and to be the master of all the planetary systems, even Dhruva loka." (Srimad Bhagavatam. 7.3. Intro)

Finally, Lord Brahma appeared before Hiranyakashipu but could not give him the boon of immortality for even Lord Brahma is not immortal. Therefore, Hiranyakashipu tried to ask for benedictions that would make him almost as good as immortal. Hiranyakashipu asked that he not meet death in any of the following conditions:

(a) By any living entity created by Lord Brahma, (b) within any residence or outside any residence, (c) during the daytime or at night, (d) on the ground or in the sky (e) by any weapon, human being, or any animal, (h) by anything living or nonliving etc.

Once having attained the powers from Lord Brahma, Hiranyakashipu began to harass all the living entities within the universe: "All the devas but Lord Vishnu, Lord Brahma and Lord Shiva came under his control and began serving him, but despite all his material power he was dissatisfied because he was always puffed up, proud of transgressing the Vedic regulations. All the brahmanas were dissatisfied with him, and they cursed him with determination. Eventually, all the living entities within the universe, represented by the devas and sages, prayed to the Supreme Lord for relief from Hiranyakashipu’s rule. Lord Vishnu informed the devas that they and the other living entities would be saved from the fearful conditions created by Hiranyakashipu. Since Hiranyakashipu was the oppressor of all the devas, the followers of the Vedas, the cows, the brahmanas and the religious, saintly persons, and since he was envious of the Supreme Lord, he would naturally be killed very soon. Hiranyakashipu’s last exploit would be to torment his own son Prahlada, who was a maha-Bhagavata, an exalted Vaishnava. Then his life would end." (Srimad Bhagavatam. 7.4. Intro)

Prahlada Maharaja, the son of Hiranyakashipu, was a great devotee and he received initiation while within the womb of his mother: "This transcendental knowledge is devotional service, and Prahlada Maharaja, while living in the womb of his mother, received instructions in devotional service from Narada Muni. Any person engaged in the service of the Lord through the instructions of a bona fide spiritual master is immediately liberated, and being free from the clutches of Maya, he is relieved of all ignorance and material desires." (Srimad Bhagavatam. 7.7. Intro)

"Regardless of the material condition in which one is situated, one can achieve this perfection. Devotional service is not dependent on the material activities of austerity, penance, mystic yoga or piety. EVEN WITHOUT SUCH ASSETS, one can achieve devotional service through the mercy of a pure devotee." (Srimad Bhagavatam 7.7.intro)

"Progress in spiritual life cannot be obstructed by any material condition. This is called ahaituky apratihata." (Srimad Bhagavatam 7.7.1)

Just see how Prahlada stayed fixed in his service despite the impediments, which were much heavier than the impediments of today: "The assistants of Hiranyakashipu struck Prahlada with sharp weapons, threw him under the feet of elephants, subjected him to hellish conditions, threw him from the peak of a mountain and tried to kill him in thousands of other ways, but they were unsuccessful. Hiranyakashipu therefore became increasingly afraid of his son Prahlada Maharaja and arrested him. The sons of Hiranyakashipu’s spiritual master, Shukracharaya, began teaching Prahlada in their own way, but Prahlada Maharaja did not accept their instructions. While the teachers were absent from the classroom, Prahlada Maharaja began to preach Krsna consciousness in the school, and by his instructions all his class friends, the sons of the demons, became devotees like him." (Srimad Bhagavatam. 7.5. Intro)

The teachers of Prahlada, Sanda and Amarka, became afraid that the students would become more and more devoted to the Lord so they informed Hiranyakashipu about Prahlada's preaching. So Hiranyakashipu decided to kill his son himself. Prahlada tried to instruct him: "Prahlada Maharaja continued: My dear father, please give up your demoniac mentality. Do not discriminate in your heart between enemies and friends; make your mind equipoised toward everyone. Except for the uncontrolled and misguided mind, there is no enemy within this world. When one sees everyone on the platform of equality, one then comes to the position of worshipping the Lord perfectly." (Srimad Bhagavatam. 7.8.9)

Controlling the mind is essential in spiritual life and is easily accomplished by becoming fixed in one's devotional service: "The only bona fide process for controlling the mind is to fix the mind by service to the Lord." (Srimad Bhagavatam. 7.8.9)

Although Prahlada tried to instruct Hiranyakashipu, he was not about take the bona fide instructions because he was not interested in devotional service: "Hiranyakashipu replied: You rascal, you are trying to minimize my value, as if you were better than me at controlling the senses. This is over-intelligent. I can therefore understand that you desire to die at my hands, for this kind of nonsensical talk is indulged in by those about to die." (Srimad Bhagavatam. 7.8.11)

Hiranyakashipu: "WHERE IS YOUR GOD?"

Prahlada replied that He is everywhere.

Hiranyakashipu: "IS HE IN THIS PILLAR, PRAHLADA???"

Prahlada: "Yes, He's everywhere."

Hiranyakashipu struck the pillar with his fists not believing Prahlada's statement; however Lord Nrsimhadeva, half-man and half-lion incarnation of the Supreme Lord, appeared with A ROAR! A great fight ensued and Lord Nrsimhadeva killed Hiranyakashipu with his nails.

Lord Nrsimhadeva killed Hiranyakashipu without violating any of the boons Hiranyakashipu had received from Lord Brahma:

(a) Hiranyakashipu was killed by Lord Nrsimhadeva who is not a living entity created by Lord Brahma nor anyone else for He is eternal and unborn.

(b) Hiranyakashipu was killed in the doorway, which is neither within any residence nor outside any residence.

(c) Hiranyakashipu was killed in the evening, which is neither daytime nor night.

(d) Hiranyakashipu was killed on the lap of Lord Nrsimhadeva, which is neither on the ground nor in the sky.

(e) Hiranyakashipu was killed by a half-man and half-lion which is neither a human nor an animal.

(f) Hiranyakashipu was killed by the nails, which are neither living nor dead nor count as weapons. Etc.

Lord Nrsimhadeva appeared in Ahovalam in South India… due to space I have not elaborated on this most auspicious holy place… please click on the link below to have a virtual tour with pictures of this Dham and how to visit this holy Dham. Included on this site the pictures of a pond where Lord Nrsimhadeva washed His hands after killing Hiranyakashipu and up to today the water remains red; the pillar from which the Lord emerged; the 9 temples of Lord Nrsimhadeva in His various forms and so forth. It’s worth a look.