Bhagavad Gita 13.18

ज्योतिषमपि तज्ज्योतिस्तमसः परमुच्यते |
ज्ञानं ज्ञेयं ज्ञानगम्यं हृदय सर्वस्य विशिष्टम्

Translation

He is the source of light in all luminaries, and is entirely beyond the darkness of ignorance. He is knowledge, the object of knowledge, and the goal of knowledge. He dwells within the hearts of all living beings.