King Prajapal requested sage Mahatapa to narrate about the manifestation of goddess Durga and the significance of her worship on navami. Sage Mahatapa replied- The mighty demon-Vetrasur had driven out deities from the heaven. All the deities went to lord Brahma and sought his help. As lord Brahma was wondering about his further course of action, suddenly goddess Durga appeared from nowhere. She held various weapons in each of her eight arms and was mounted on a ferocious lion. Lord Brahma was relieved as he was confident that Goddess Durga would certainly kill Vretasur. Finally goddess Durga indeed killed the dreaded demon without much difficulty. Later on, all the deities requested her to make Himalaya mountain as her abode to which she agreed. This particular place, in course of time became famous as Nandadevi. One who worships goddess Durga on the auspicious day of navami gets her blessings.