Valmiki Ramayana Bala Kanda Sarga 2 Shloka 37

त्वत्कृता composed by you, रामायणकथा the Ramayana story, यावत् as long as, प्रचरिष्यति prevails, तावत् till then, त्वम् you, ऊर्ध्वम् the upper world, heaven, अधश्च the nether world, मल्लोकेषु in my (Brahmaloka), निवत्स्यसि will reside.

So long as the story of the Ramayana composed by you is remembered in this world, you will live in the upper world, the nether world and Brahmaloka".