Bhagavad Gita Chapter 8, Verse 24

अग्निर्ज्योतिरह: शुक्ल: षण्मासा उत्तरायणम् | तत्र प्रयाता गच्छन्ति ब्रह्म ब्रह्मविदो जना: ||

agnir jyotir ahaḥ śuklaḥ ṣaṇ-māsā uttarāyaṇam tatra prayātā gacchanti brahma brahma-vido janāḥ

Fire, light, daytime, the bright fortnight, the six months of the northern solstice—departing by this path, those who know Brahman go to Brahman.

Krishna describes the path of light: 'Agnir jyotir ahah shuklah shanmasa uttarayanam'—fire (agnih), light (jyotih), daytime (ahah), the bright fortnight (shuklah), the six months (shanmasa) of the northern solstice (uttarayanam). 'Tatra prayata gacchanti brahma brahma-vido janah'—departing (prayatah) by that path (tatra), those who know Brahman (brahma-vidah) go (gacchanti) to Brahman (brahma). This is the path of light—the luminous path that leads to liberation. Those who know Brahman and depart during these auspicious times (fire, light, day, bright fortnight, northern solstice) go to Brahman and don't return. This is the path of liberation—no return to the material world. Understanding this helps you prepare: cultivate knowledge of Brahman and aim for these auspicious times, though ultimately it's the state of consciousness that matters most.