Immortality

Thereafter, I asked a boon of the lotus-eyed Rama, saying, 'O slayer of foes, Rama, may I live as long as the history of thy deeds
remaineth extant on earth!" Thereupon he said, 'So be it. O represser of foes, O Bhima, through the grace
of Sita also, here all excellent objects of entertainment are supplied to me, whoever abide at this place. Rama reigned for the thousand and ten hundred years. Then he ascended to his own abode.

Vana Parva: Section 147