Bhagavad Gita Verse 25, Chapter 8

dhoomo raatristathaa krishnaha shanmaasaa dakshinaayanam |
tatra chaandramasam jyotiryogi praapya nivartate || 25 ||
 
Smoke, night, darkness and the southern movement comprising six months; the yogi (travels through) that path, attains the light of the moon, to return.
 
dhoomaha : smoke
raatrihi : night
tathaa : and
krishnaha : darkness
shanmaasaa : comprising six months
dakshinaayanam : southern movement
tatra : through that path
chaandramasam : of the moon
jyotihi : light
yogi : yogi
praapya : attains
nivartate : return
 
We saw earlier that jeevas who have practised single-pointed devotion travel on the path of light, attain the abode of Lord Brahma, and eventually achieve liberation. Now, Shri Krishna describes the path of the jeeva who has performed good deeds in its lifetime, but had not practiced devotion. This path is called the path of the moon or the lunar path.
 
The jeeva is guided on this path by the deities who preside over the smoke of the pyre, night, the dark lunar fortnight and the six months between summer and winter. Having travelled through the lunar path, these jeevas attain a lower realm called Chandraloka or the abode of the moon. In modern language, this is nothing but heaven. The jeeva enjoys heavenly pleasures, which are the fruits of its earthly actions. Unlike the jeeva in Lord Brahma’s abode, this jeeva returns to earth once the fruits of its good actions have depleted.
 
Both the dark lunar fortnight and the period between summer and winter are relatively less auspicious than their brighter counterparts. But many festivals including Maha Shivraatri and Krishna Janmaashtami are celebrated during the dark lunar fortnight.
 
Shri Krishna summarizes the difference between the two paths in the next shloka.

Bhagavad Gita Verse 24, Chapter 8

agnijyotiraha shuklaha shanmaasaa uttaraayanam |
tatra prayaataa gachhanti brahma brahma vido janaahaa || 24 ||
 
Fire, light, day, the bright (fortnight of the month), the northern movement comprising six months; those people who have departed through that path, knowers of brahman attain brahman.
 
agnihi : fire
jyotihi : light
ahaha : day
shuklaha : bright
shanmaasaa : comprising six months
uttaraayanam : northern movement
tatra : through that path
prayaataa : one who has departed the body
gachhanti : attain
brahma : brahman
brahmavidaha : knowers of brahman
janaahaa : people
 
Shri Krishna describes the journey that the individual soul or jeeva takes after death in this and the next shloka. Each jeeva is allocated one of two paths based on its actions while on this earth. Here, he speaks about the path taken by those who have practiced single-pointed devotion to Ishvara, indicated by the phrase “knowers of brahman”.
 
It is said that Ishvara has appointed special deities to guide the jeeva to the abode of Lord Brahma after its body has ceased to function. Agni, jyoti, shukla and uttaraayan are symbols that indicate the deities who preside over fire, light, the lunar fortnight and the six month period between winter and summer. The jeeva resides in Lord Brahma’s abode until dissolution, after which it is liberated. In other words, it “attains brahman”.
 
In India, Uttaraayana is considered highly auspicious. Its beginning is celebrated with the Makar Sankraanti festival. The lunar fortnight of each month is also the time in which most Indian festivals are celebrated including Navaratri and Guru Purnima.
 
Next, Shri Krishna described the second path that jeevas take after death.