Sankaracarya's Vivekachudamani 565

विलक्षणं यथा ध्वान्तं लीयते भानुतेजसि ।

तथैव सकलं दृश्यं ब्रह्मणि प्रविलीयते ॥

vilakṣaṇaṃ yathā dhvāntaṃ līyate bhānutejasi |

tathaiva sakalaṃ dṛśyaṃ brahmaṇi pravilīyate ||

(Sankaracarya's Vivekachudamani 565)

Just as darkness---which is distinctly different from sunlight---vanishes in the sun's effulgence, so too, this entire objective universe vanishes into Brahman.

The Lord is just like the effulgent sun. Consequently, whenever the Supreme Personality of Godhead is present, there cannot be darkness or ignorance. Actually this dark universe is illuminated by the sun, but the sun and moon simply reflect the bodily effulgence of the Supreme Lord. In Bhagavad-gītā (7.8) the Lord says, prabhāsmi śaśi-sūryayoḥ: "I am the illuminating energy of both the sun and the moon." The conclusion is that the origin of all life is the bodily effulgence of the Supreme Personality of Godhead. This is also confirmed in Brahma-saṁhitā: yasya prabhā prabhavato jagad-aṇḍa-koṭi (Bs. 5.40). Being illuminated by the bodily effulgence of the Supreme Personality of Godhead, everything is freed from all darkness.