In the beginning of the world, Brahmaa Jee poduced 10 Maanas Putra (mind children). One of them was Maharshi Bhrigu. Maharshi Bhrigu also produced a brainchild named Atharvaa Muni. Atharvaa Muni was married to Maharshi Kardam's one of nine daughters - Chitti. Dadheechi was their son. Thus he was the grandson of Bhrigu Rishi.
Once there was a great Asur, Vritraasur. He was very mighty and Devtaa were not able to kill him. Devtaa went to Brahmaa Jee to ask for his help. Brahmaa Jee said - "You go to Maharshi Dadheechi, he will help you out of this problem.
He is a great Yogee. Because of his Tap, he has so much power in his bones that a weapon made out of his bones can kill Vritraasur. Tell him, "We need your bones for the welfare of this world." Then ask Vishwakarmaa to make Vajra (thunderbolt) out of his bones. You will definitely be able to kill Vritraasur from that Vajra." Devtaa went to Maharshi Dadheechi.
Seeing Devtaa coming to him, Maharshi Dadheechi welcomed them and asked the reason for their coming to him. Devtaa said - "Hey Maharshi, we need your bones for the welfare of this world." Dadheechi was a very kind Rishi. He said - "Without giving my life I cannot give you my bones. I am ready to give my life for the welfare of this world. I will leave this body by Yog. After that you may take my body and do whatever you like."
After saying this he sat in meditation, and after some time he left his body through Yog. Devtaa took his body and called Vishwakarmaa to make a Vajra out of his bones. Vishwakarmaa soon made a Vajra out of his bones. Carrying that Vajra, Indra came to battlefield and killed Vritraasur from that Vajra.
[One should not hesitate to give even one's life for the welfare of the community or world.]