Matsyapurana 161.4

161.4

tataḥ śamadamābhyāṃ ca brahmacaryeṇa caiva hi
brahmā prīto 'bhavattasya tapasā niyamena ca //

Sûta said:—O Brâhmanas! The demon Hiraṇyakaśyapu was the most ancient progenitor of the Daityas during the Satyayuga (the golden age). He practised severe austerities for 11,000 years, taking his bath regularly and then plunging himself in water neck deep and observed the vow of silence. He led a life of continence restraining and controlling his passions and was very humble. Brahmâ was highly pleased with his devotion.—2-4