Valmiki Ramayana Sundara Kanda Sarga 39 Shloka 41
Original Shlokaमम पृष्ठगतौ तौ च चन्द्रसूर्याविवोदितौ। त्वत्सकाशं महासत्त्वौ नृसिंहावागमिष्यतः।।5.39.41।।
1 source checked for this shloka
महासत्त्वौ both great men, नृसिंहौ both lions among men, तौ च and both, मम my, पृष्ठगतौ on my back, उदितौ just risen, चन्द्रसूर्याविव like Sun and Moon, त्वत्सकाशम् to your presence, आगमिष्यतः will come.
"Both the valiant Rama and Lakshmana, lions among men, looking brilliant like Sun and Moon will come to you riding on my back.