As per yajurveda Suryo brahman . The brahman which is unimaginable can be quoted as sun . Sun illuminates on one side of the moon while the other side is dark . So two type of pleasures are there , 1. Chidanand 2. Sadananda .
study starts with material as science , rises then to logical philosophy giving the thought to spirituality and finally theology comes as devotion .
Thirteen devas as 1. Brahma 2. Rudra 3.chandra 4. Dic 5. Agni 6. Vayu 7. Indra 8. Surya 9. Upendra 10. Varuna 11. Prajapati 12. Ashvini 13. Mrityu and all pervaded by vasudeo 14 . the parmatma .
Here two pleasures chidananda , eternal pleasure as full moon and sadananda , the eternal rest as full dark moon is taken . In detail we can refer to ved-richas by bhagvatam and gita as follow :
What they [karma-kânda] enjoin [to be done], what they [upâsana-kânda] indicate [as being the object of devotion], what aspects they describe or what alternatives they [jñâna-kânda] thus literarily offer [as philosophy], the heart of this matter is in this world not known by anyone else but Me . I am the object of worship, the concern of the enjoined action and the alternative that is offered and explained away . The transcendental sound vibration of the Vedas establishes Me as being their meaning and elaborately describes the material duality as simply being the illusory one has to emasculate to ultimately become happy.' Bhagvatam 42 , 43 /21 / 11 canto
the southern path of the sun (the southern solstice), the Yogi returns.
The bright and the dark paths of the world are verily thought to be eternal; by the one
(the bright path) a person goes not to return again, and by the other (the dark path) he returns.
The bright path is the path to the gods taken by devotees. The dark path
is of the manes taken by those who perform sacrifices or charitable acts with the expectation of rewards. Gita 25 , 26 /8 ch