Chapter 13 · The Field and the Knower · Krishna said
Bhagavad Gita 13.18 — Light of all lights
ज्योतिषामपि तज्ज्योतिस्तमसः परमुच्यते। ज्ञानं ज्ञेयं ज्ञानगम्यं हृदि सर्वस्य विष्ठितम् ॥
jyotiṣāmapi tajjyotistamasaḥ paramucyate | jñānaṃ jñeyaṃ jñānagamyaṃ hṛdi sarvasya viṣṭhitam ||
Meaning
It is the light of all lights and is said to be beyond darkness. It is knowledge, what is to be known, and the goal of knowledge, seated in the hearts of all.
In today's life
The light you seek in the outside world already shines within your own heart.