Bhagavad Gita Chapter 13.34
yathā prakāśayaty ekaḥ
kṛtsnaḿ lokam imaḿ raviḥ
kṣetraḿ kṣetrī tathā kṛtsnaḿ
prakāśayati bhārata
Translation
O son of Bharata, as the sun alone illuminates all this universe, so does the living entity, one within the body, illuminate the entire body by consciousness.