Everything shines after Him

Brihadaaranyaka Upanishad has a wonderful explanation about "self" the fifth and ultimate source of light available for human beings. 

A self realized soul, a great sage, came to King Janaka's court. King Janaka requested the sage to talk about the light of lights that lights a man's way in the world.

Sage said: 

There are five lights: Sun lights a man's way during the day, Moon at night, Fire lights his way when there is neither the sun nor the moon and Voice can help to some extend to know a man's way. ( When it is dark, sounds can help us move to that place from which the sound came). But when it is pitch dark, and all sounds have stopped, "Self" or the "knowing one" or "inner light" is the light that lights a man's way. 

Then he continued the explanation of this "seer" or "master of all" or the "ultimate controller" of everything. It is this "self" who sees us when we are awake, when we are dreaming, and when we are fast asleep. Because of this seer, we get up in the morning and say " I had a good night's sleep". When we were sleeping, this self was still up watching our body and senses go to sleep. This is the "I" that knew that we slept well. There can never be an end to the seeing of this "Seer". 

He is eternal and this knowing of the "knower" is eternal. He cannot be destroyed by arrows, sharp objects, fire or water. This "seer" has no attachment to anything, He is not bound, He does not suffer, He is beyond all the three Gunaas so that good and evil do not affect Him. And we call Him God. He is the Bhoothabhavyeshan, Lord of the past and future, He is the one whom fear is afraid of, and when you know Him, you become Him.

King Janaka: Thank you venerable sage. Please bless me to become a Jeevamuktha, a liberated soul!

Sage: Thathhasthu! Let that be!

Na thathra sooryo bhaathi na chandrathaarakam

nema vidyutho Bhaanthi kuthoyamaagni:

thameva bhaantham anubhaathi sarvam 

thasya bhaasa  sarvamidam vibhaathi

The sun does not shine there, nor do the moon and the stars, nor do lightnings shine and much less this fire. When He shines, everything shines after Him; by His light, all these shine. 

ന തത്ര സൂര്യോ ഭാതി ന ചന്ദ്രതാരകം 

നേമാ വിദ്യുതോ ഭാന്തി കുതോയമഗ്നി: 

തമേവ ഭാന്തം അനുഭാതി സര്‍വം 

തസ്യ ഭാസാ സര്‍വമിദം വിഭാതി