According to the Purāṇas, Lord Viṣhṇu appeared as Narasimha on the Chathurdaśhi day in the month of Vaiśhākha and this day is celebrated as Narasimha Jayanthi. Narasimha means half man and half lion. Lord Viṣhṇu took this incarnation to rescue Prahlādha from demon Hiraṇyakaśhipu and it is the fourth avatar of Lord Viṣhṇu. Demon Hiraṇyakaśhipu had obtained a boon from Brahma that he could not be killed either by man or beast, either in day or night, either from inside or outside. Having attained this powerful boon, he conquered heaven, earth and declared himself as God and terrorized people to worship him and not Viṣhṇu.

Hiraṇyakaśhipu’s son Prahlādha was a staunch devotee of Lord and he did not listen to the words of his father. Hiraṇyakaśhipu’s efforts to change his son were in vain. His attempts to kill his son were also not fruitful as Lord Viṣhṇu saved Prahlādha every time. Fed up with his son, he challenged Prahlādha and looking at a stone pillar, asked, ‘If your god is universal, is he in this pillar also?’ Prahlādha answered, ‘He is present in the pillar and even in the rust.’ Hearing this Hiraṇyakaśhipu slashed hard on the pillar with a sword. Suddenly, Lord Viṣhṇu emerged from the pillar in the form of a Narasimha killed the demon by keeping him in his lap and tearing his heart with bare hands thus overcoming the boon that the demon had attained from Brahma.

Devotees fast on Narasimha Jayanthi day and visit Lord Viṣhṇu temples. People also help the needy, offer Annadhānam (donate food to poor). The belief is those people who observe Narasimha Jayanthi vratham shall attain the ‘Vaikunṭha’ – abode of Viṣhṇu.