Bhagavad Gita Verse 12, Chapter 15

yadaadityagatam tejo jagadbhaasayatekhilam |
yachhandramasi yacchaagnau tattejo viddhi maamakam || 12 ||
 
That splendour which resides in the sun and illumines the entire world, that which is in the moon and in fire, know that splendour to be mine.
 
yat : that
aadityagatam : resides in sun
tejaha : splendour
jagat : world
bhaasayate : illumines
akhilam : entire
yat : that
chandramasi : in the moon
yat : that
cha : and
agnau : in fire
tat : that
tejaha : splendour
viddhi : know
maamakam : mine
 
So far we learned about the nature of the individual soul, the jeeva. But if that is all we focus on, we will have incomplete knowledge about our true nature. When we look around us, we see the world in all its beautiful yet complex glory. We need to investigate into the true nature of the world, and realize our identity and connection with that as well. With this view in mind, Shri Krishna now begins to explain his connection with the world around us.
 
He starts this topic by asserting that the splendour of the sun, the moon, and of fire is possible only because of Ishvara's splendour. We have tremendous awe for the sun's energy, without which life on this earth will not be possible. Shri Krishna says that the sun’s splendour is not its own. It comes from the splendour of Ishvara. Symbolically, the sun represents the organs of perception such as the eyes, ears, nose and so on. Therefore, whenever any sentient being in this world, from a single celled amoeba to a human being becomes aware of something, that awareness, that consciousness, is the power of Ishvara at work.
 
So whenever we see awareness manifest itself in any organism, we should remind ourselves that the one Ishvara giving awareness to us is the same Ishvara giving awareness to the organisms in the world. In this manner, we can realize the identity of our nature with the world through the common link of awareness.
 
Furthermore, both the moon and fire derive their energy and splendour from the sun. The moon reflects the light of the sun. Fire also is the manifestation of the sun's energy on a much smaller scale. Therefore, energy in any form, whether it is dazzling like the sun, cooling like the moon, or warm like fire, is nothing but Ishvara’s energy. How does this energy manifest itself in the world? Shri Krishna explains that in the next shloka.

Bhagavad Gita Verse 6, Chapter 15

na tadbhaasayate sooryaa na shashaanko na paavakaha |
yadgatvaa na nirvatante taddhaamam paramam mama || 6 ||
 
That in which the sun does not illumine, nor the moon, nor fire, that is my supreme abode. Having attained that, there is no return.
 
na : not
tat : that
bhaasayate : illumines
sooryaha : sun
na : not
shashaankaha : moon
na : not
paavakaha : fire
yat : which
gatvaa : attained
na : not
nirvatante : return
tat : that
dhaamam : abode
paramam : supreme
mama : my
 
Shri Krishna listed the qualifications of a seeker in the prior shloka, and asserted that one who takes his refuge will attain his abode. He now provides the location, the address of that abode. He says that there is no sun, no moon, no fire, in other words, no source of light in his abode. Initially we would feel a little frightened if we take the literal meaning of this shloka. Even cavemen were able to access some light source in the form of the sun, the moon, or fire from a wooden torch. Why would anyone want to go to such a place?
 
The sun, the moon and fire have symbolic interpretations which are extremely relevant here. The sun is the presiding deity of our intellect, the moon of our mind and emotions, and fire of our physiological functions. The one who has sought refuge in Ishvara automatically gives up affinity to his body, mind, intellect, ego (which resides in the intellect) and physiological functions. If this affinity, the root of all our sorrow, is given up, such a person will never again get caught in the wheel of birth of death, in the cycle of samsaara. This is liberation.
 
So then, this is the abode of Ishvara, of self realization, of liberation. Having reached there, the liberated person does not come back to the state of ignorance. He never gets deluded again. He never identifies or develops affinity with body, mind, intellect and the world. The duality, the pairs of opposites, the dvandva that was mentioned before, is nothing but the world. For such a person, neither joy nor sorrow, neither pain nor pleasure, neither friend nor enemy, nothing can destabilize him. This is liberation.