Mbh 3.100.2a

“Lomasa said, ‘Listen now, O king, to the excellent and wonderful and extraordinary history of Agastya, as also, O monarch, about the prowess of that Rishi of immeasurable energy. There were in the Krita age certain tribes of fierce Danavas that were invincible in battle. And they were known by the name of Kalakeyas and were endued with terrible prowess. Placing themselves under Vritra and arming themselves with diverse weapons they pursued the celestials with Indra at their head in all directions. The gods then all resolved upon the destruction of Vritra, and went with Indra at their head to Brahma. And beholding them standing before him with joined hands, Parameshthi addressed them all and said, “Everything is known to me, ye gods, about what ye seek. I shall indicate now the means by which ye may slay Vritra. There is a high-souled and great Rishi known by the name of Dadhicha. Go ye all together unto him and solicit of him a boon. With well-pleased heart, that Rishi of virtuous soul will even grant you the boon. Desirous as ye are of victory, go ye all together unto him and tell him, ‘For the good of the three worlds, give us thy bones.’ Renouncing his body, he will give you his bones. With these bones of his, make ye a fierce and powerful weapon to be called Vajra, endued with six sides and terrible roar and capable of destroying even the most powerful enemies. With that weapon will he of a hundred sacrifices slay Vritia. I have now told you all. See that all this is done speedily.’ Thus addressed by him, the gods with the Grandsire’s leave (came away), and with Narayana at their head proceeded to the asylum of Dadhicha. That asylum was on the other bank of the river Saraswati and covered with diverse trees and creepers. And it resounded with the hum of bees as if they were reciting Samans. And it also echoed with the melodious notes of the male Kokila and the Chakora.