Narasingha Dev is the half-man half-lion avatar of Lord Vishnu. He is the Lord who bestows protection, removes enemies and evil spirits from his devotees, and protects them from Maya, or illusion.
When his pure devotee Prahlada Maharaja, who was mere a boy, was threatened by own his father, King Hiranyakashipu, for no other reason except for his devotion to Lord Vishnu, Lord Vishnu appeared on earth as the dreadful Narasinghadev.
The cruel Hiranyakashipu had a boon that he could be killed neither by a man nor an animal, not in the day and nor the night, neither inside nor outside, neither on the ground nor in the air, and not by any weapon.
It was at dusk, when it is no longer daytime and not yet night, when Lord Vishnu appeared to protect Prahlada. Neither a man nor an animal, his lion head roared as he displayed his large teeth and his sharp nails shone as he grabbed Hiranyakashipu, placing him on his human lap – neither in the air nor on the ground. With no weapon, except for his sharp, long nails, he killed the evil king and saved the life of the young Prahlada.
Narasingha Dev is very fierce to the enemies (impurities) but very gentle and sweet to those whose heart is pure. So sweet, that one devotee of Lord Narasimha, Paramahaṁsat yati Jiyar, wrote in a prayer:
"O Lord Nṛsiṁha, O Mukunda, Madhusūdana, Murāri, Vāmana, you are the shelter of the surrendered souls. O Lord of the demigods, cause of all causes, please do not neglect me. Kindly fulfill my desire of passing my whole life chanting your holy names."
Here is a moving dramatic telling of the 5000-year-old saga which will purify and uplift all listeners by Emmy-nominated actor Sripad Jagannatha Das. Das is a lifelong Bhakti yogi and devotee of Sri Krsna.