Diti was filled with grief when she came to known about her son’s (Hiranyaksha) death, who was killed by lord Vishnu.
Nirhaddaitya, who was the maternal uncle of Prahlada consoled her an promised to avenge the death of Hiranyaksha. He thought to destroy the vedic religion. According to him the deities derived their strength and power from this very vedic religion. He planned to eliminate the priestly class-brahmins, so that the chances of ‘Yagyas’ being performed becomes extinct and the deities were starved to such an extent that they became weak and powerless. Thinking that then it would not be very difficult to kill the ‘weak’ deities.
Nirhaddaitya arrived at Kashi to execute his plan, which during those time was the chief center of the brahmins. He attained the form of a tiger and stationed himself in a nearby forest. He used to kill any brahmin who used to come over there to collect ‘Kusha’ grass and fuel. With the help of his illusionary powers he used to attain the form of a hermit during the daytime and lived among them. But during the night, he used to enter into the houses of the brahmins in the form of a tiger and used to devour them.
On one night of Shivaratri, when a brahmin was busy worshipping Lord Shiva, Niraddaitya who was in the form of a tiger entered the temple. But, since the brahmin was engaged in the worship of Lord Shiva, he could not harm the brahmin. Lord Shiva emerged from the very Shivalinga,
which the brahmin was worshipping and punched the demon with his clenched fist, so hard that he died.