Valmiki Ramayana Kishkindha Kanda Sarga 43 Shloka 38
Original Shlokaगभस्तिभिरिवार्कस्य स तु देशः प्रकाशते। विश्राम्यद्भिस्तपस्सिद्धैर्देवकल्पैः स्वयंप्रभैः।।4.43.38।।
1 source checked for this shloka
देवकल्पैः equal to gods, स्वयंप्रभैः selfeffulgent ones, विश्राम्यद्भिः by the living, तपस्सिद्धैः perfected by austerities, सः देशः that place, अर्कस्य Sun's, गभस्तिभिरिव like the Sun rays, प्रकाशते shines.
'That (Sunless) land shines like the radiance of the Sungod with the presence of selfeffulgent ascetics who have attained perfection in penance.