Matsyapurana 146.42

146.42

sā tu labdhavarā devī jagāma tapase vanam
daśa varṣasahasrāṇi sā tapo ghoramācarat //

Diti, after being thus blessed, repaired to the forest where she practised severe austerities for ten thousand years At the close of her period of austerities, she begot a son who was of wonderful deeds, unconquerable and invulnerable even by the thunderbolt. He became thoroughly conversant in all the Śastras as soon as he was born and devoutly said to his mother —"mother! direct me what I should do for you"—42 44