Mbh 14.11.2a

"'Vasudeva said, "All crookedness of heart leads to destruction (perdition?) and all rectitude leads to Brahman (spiritual excellence). If this and this only is the aim and object of all true wisdom, then what can mental distraction do (to one who understands this)? Thy Karma has not yet been annihilated, nor have thy enemies been subjugated, for thou dost not yet know the enemies that are still lurking within thine own flesh. I shall (therefore) relate to thee truly as I have heard it, the story of the war of Indra with Vritra as it took place. In ancient times the Prithivi (earth), O king, was encompassed by Vritra, and by this abstraction of earthly matter, the seat of all odour, there arose bad odours on all sides, and the Performer of a hundred sacrifices (Indra), being much enraged by this act, hurled his thunderbolt at Vritra. And being deeply wounded by the thunderbolt of mighty Indra, Vritra entered into the (waters), and by doing so he destroyed their property. The waters being seized by Vritra, their liquid property left them. At this Indra became highly enraged and again smote him with his thunderbolt. And he (Vritra) smitten by the thunderbolt by the most powerful Indra betook himself to the Jyoti (luminous matter) and abstracted its inherent property. The luminous matter being overwhelmed by Vritra and its property, colour and form being thereby lost, the wrathful Indra again hurled his thunderbolt at him. And thus wounded again by Indra of immeasurable power, Vritra entered all on a sudden into the Vayu (gaseous matter). and thereafter made away with its inherent property. And this matter being overpowered by Vritra and its property, viz., touch being lost, Indra became again filled with wrath and flung his thunderbolt at him.