In the Vana Parva of the Mahabharata, Shiva disguises himself as a hunter and fights with Arjuna. Finally Shiva reveals himself, and tells Arjuna about Arjuna's past birth as the sage Nara:
Thou wert in thy former life Nara, the friend of Narayana. In Vadari wert thou engaged in fierce ascetic austerities for several thousands of years. In thee as well as in Vishnu--that first of male beings--dwelleth great might. Ye both, by your might, hold the universe; O lord, taking up that fierce bow whose twang resembled the deep roar of the clouds, thou, as well as Krishna, chastisedest the Danavas during the coronation of Indra. Even this Gandiva is that bow, O son of Pritha, fit for thy hands.
For those who don't know, the sage Nara was the twin brother of the sage Narayana, an ancient incarnation of Vishnu who was the son of Yama god of death and the founder of the Pancharatra movement which was a precursor to modern Vaishnavism, as I discuss here.
But my question is, what is the story of Nara and Narayana fighting the Asuras at the time of Indra's coronation, with Nara using the Gandiva bow? In this chapter of the Virata Parva of the Mahabharata, Arjuna lists some of the previous owners of the Gandiva bow:
Shiva held it first for a thousand years. Afterwards Prajapati held it for five hundred and three years. After that Sakra, for five and eighty years. And then Soma held it for five hundred years. And after that Varuna held it for a hundred years. And finally Partha, surnamed Swetavahana, hath held it for five and sixty years.
So did one of these gods give the Gandiva bow to the sage Nara in order to fight the Asuras? By the way, I do know one occasion where Nara and Narayana fought the Asuras, described in this chapter of the Adi Parva of the Mahabharata, but that was after the churning of the ocean, not Indra's coronation.