Bhagavad-gītā 13.18
BG 13.18
Open the full passageज्योतिषामपि तज्ज्योतिस्तमसः परमुच्यते । ज्ञानं ज्ञेयं ज्ञानगम्यं हृदि सर्वस्य विष्ठितम् ॥१८॥
Sanskrit
jyotiṣām api taj jyotis tamasaḥ param ucyate jñānaṁ jñeyaṁ jñāna-gamyaṁ hṛdi sarvasya viṣṭhitam
Translation
He is the source of light in all luminous objects. He is beyond the darkness of matter and is unmanifested. He is knowledge, He is the object of knowledge, and He is the goal of knowledge. He is situated in everyone's heart.