As per Sage Sandipani’s request, Lord Krishna and Balarama went to bring his son back. They went to the ocean shores of Prabhaasa and ordered the god of the ocean to give back Sage Sandipani’s son. The ocean replied, “The boy is not in my grip. He was taken away by demon Shankha. He has a holy conch-shell named Panchajanya and he lives inside it.” Lord Krishna entered the ocean and killed Shankhasur, but He did not find the boy there. So, He took the conch-shell and went to Yamapura, the kingdom of Yamaraja. When Krishna blew the conch, Yamaraja welcomed him. When He ordered the boy’s return, Yamaraja returned Sage Sandipani’s son. Once he was brought back to life, Krishna and Balarama handed the boy over to their Guru Sandipani. From that day onwards, Lord Krishna carried the conch-shell with him. He even blew conch-shell, Panchajanya along with Arjun’s conch-shell, Devdatta, signalling the start of the war of the Mahabharata.