Significance of Narasimha Avatar
When Prahlad returned home from school for first summer vacation, his dad Hiranya Kasipu asked him what is the best or the essense of what he learned in school.
Prahalad, to his dad surprise, replied that the essence of education is to glorify 'Sriman Narayana'. Also recited all 1000 names Sahasra namam. *Any other parent in his place, would have been delighted to hear this. Contrary to that though, Hiranya Kasipu tried to kill him if Narayanan was not present in the pillar he built - he was certain He was not there as he, Hiranyan was the one putting each and every brick of that pillar, as Azwar says*
Alandhu itta thoonai avan thatta, ange
Valarndittu vaal ukkra singa uruvai
Ulanthottu, hiranyan onmaarvu agalam
Pilandhitta kaigalaal chappaani
Pei mulai undaane chappaani (Periazhwar)
As we know Brahma had given the very special boon to Hiranya Kasipu. The Lord took it upon Himself to ensure Brahma's words didn't go untrue and hence took that form, chose the twilight time, and the entrance. He didn't want a situation where Brahma's boon to Hiranyan wasn't fulfilled and also to prove Prahalad's words, *the omnipresent Lord*. Hence, He gave up His Kaarunyamugam (Ever compassionate form) and took this half Human, half Lion form, not a preplanned one like Rama Avatar or Krishna Avatar where He chooses His parents and place to be born.
Engumulan Kannan endra makanaikkaaindhu
Ingilaiyaal endru Hiranyan Thoonpudaippa
Angu Appaozhudhey avan Veeyathondriya En
Singapiraan Perumai Arayum Seermeithey
Atharvana Vedam explains Lord Narasimhar as Vidhyut Shakthi or some sort of "electricity", not without a reason. Just as electricity immediately holds on to anyone who touches it, He is also referred to someone who "Holds on to the hand beating him".
In Hiranyan's tussle with the Lord, Sriman Narayana held on to Hiranya's hand and with His other hand, held Hiranya's head. Why would He do that? That is because of the compassion for His devotees. Thinking "why would this unwise person want to fight with Me, with this one grip of Mine, let Me see if he realizes his blunder. If he surrenders, then We will not kill him" He demonstrates His strength and held on very firmly. Even when He is in such a ferocious form, He displays so much of compassion, imagine how kind He is in his other softer forms.
In describing His speed, He is compared to how swiftly the clouds are moving. That is the speed He came in and held Hiranyan. Alas though Hiranyan would not repent even then.
Even after laying Hiranyan on his lap, the Lord gave him yet another chance. There aren't words to explain his extreme compassion towards his subjects. He told Himself "if Hiranyan committed all his sins superficially just uttering those but not from his heart, then let's pardon him". He then goes to feel the heart and finding all the hatred in the heart is when the Lord decides to kill him.
Until and even after the last minute He gives the opportunity to surrender to Him and He makes it too easy for us to surrender. Its then up to us to pick up the opportunity and go to Him. He then goes on to destroy Hiranyan.
Even after vanquishing Hiranyan, the ferocity of Lord Narasimha didn't cool down. The Devas feared getting anywhere near him. They asked Sri Lakshmi to go and soften him, she too was scared. She said it's best to send Prahaladan.
Prahladan went and sat on the lap of the Lord, who hugged him and offered him a boon. Prahaladan chuckled and said he isn't stupid to ask for a boon and restrict the blessings of the Lord and would instead let the Lord decide what is needed. *He pointed to the fate of his father Hiranyan, who asked for a specific boon and now lay destroyed just by that boon. *
When the Lord advises Prahaladan to take the throne, Prahaladan wasn't sure if he wanted to be seated on the throne from where his father did all the slandering of the Lord. Sensing this, the Lord himself sits on the throne to cleanse it of all the sins and then gives way to Prahaladan to take the throne. Given its the seat where the Simham Himself sat, it's hence called Simhaasanam, so are all thrones of the kings.
(Compiled by Sri T. Natarajan from the discourses of Sri Krishna Premi Anna's Srimad Bhagavatham dicourses and writings of Sri Mukkur Lakshmi Narsimachariyar)