The Vajra in The Puranas
Many later Puranas describe the Vajra, with the story modified from the Rigvedic original. One major addition involves the role of the Sage Dadhichi. According to one account, Indra, the King of the devas was once driven out of devaloka by an asura named Vritra. The asura was the recipient of a boon whereby he could not be killed by any weapon that was known till the date of his receiving the boon and additionally that no weapon made of wood or metal could harm him.) Indra, who had lost all hope of recovering his kingdom was said to have approached Shiva who could not help him. Indra along with Shiva and Brahma went to seek the aid of Vishnu. Vishnu revealed to Indra that only the weapon made from the bones of the sage Dadhichi would defeat Vritra. Indra and the other devas therefore approached the sage, whom Indra had once beheaded, and asked him for his aid in defeating Vritra. Dadhichi acceded to the devas' request but said that he wished that he had time to go on a pilgrimage to all the holy rivers before he gave up his life for them. Indra then brought together all the waters of the holy rivers to Naimisharanya, thereby allowing the sage to have his wish fulfilled without a further loss of time. Dadhichi is then said to have given up his life by the art of Yoga after which the Devas fashioned the Vajrayudha from his spine. This weapon was then used to defeat the asura, allowing Indra to reclaim his place as the King of devaloka
Another version of the story exists where Dadhichi was asked to safeguard the weapons of the devas as they were unable to match the arcane arts being employed by the asuras to obtain them. Dadhichi is said to have kept at the task for a very long time and finally tiring of the job, he is said to have dissolved the weapons in sacred water which he drank.) The devas returned a long time later and asked him to return their weapons so that they might defeat the asuras, headed by Vritra, once in for all. Dadhichi however told them of what he had done and informed them that their weapons were now a part of his bones. However, Dadhichi, realising that his bones were the only way by which the devas could defeat the asuras willingly gave his life in a pit of mystical flames he summoned with the power of his austerities. Brahma is then said to have fashioned a large number of weapons from Dadhichi's bones, including the Vajrayudha, which was fashioned from his spine. The devas are then said to have defeated the asuras using the weapons thus created.
There have also been instances where the war god Skanda (Murugan) is described as holding a Vajra. Skanda is also the name of a Bodhisattva in Mahayana Buddhism who wields a Vajra.
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