The city of Champaka-nagari
In the ancient city of Champaka-nagari, rich in gardens of the champa flower, ruled the dharma-loving king Vaikhanasa. He was a Vaishnava by mother's milk, kept every Ekadashi from boyhood, and his sabha was famous for the recitation of Vishnu Sahasranama at dawn. His pitr — father — had ruled before him and, though largely dharmic, in his youth had once ordered a Brahmin banished on a false charge; that single papa still burned in the accounts of Yama, though the son had never known of it.
The dream at midnight
On a Margashirsha night in the palace, Vaikhanasa slept lightly, for a strange oppression sat on his chest. Just past midnight his father appeared to him in a form of terrible suffering — chained, blackened, weeping. 'Beta, if any love for me still lives in you, save me. I am tormented in naraka for a papa whose weight I did not know in life. There is one vrat that can lift it. Find the rishi Parvata; he will tell you.' The king woke with tears already on his face and by dawn had left the palace for the ashram of Parvata Muni upon the slopes near the sacred Champakaranya.
The counsel of Rishi Parvata
Rishi Parvata, seeing the whole matter in tapa-drishti, sighed and said, 'Rajan, your father speaks truly. The Ekadashi that approaches in the bright half of Margashirsha is called Mokshada — the giver of moksha. It is that very day on which, in an age to come, Bhagwan Krishna will speak the Bhagavad Gita to Arjuna between the two armies at Kurukshetra. Its vrat has this rare power: whatever punya the vrati earns, he may with a sankalp assign to another soul — living or gone. Fast the whole day, keep jagran with Gita paath, do tulsi archana at midnight upon the shalagram, and at Dwadashi parana dedicate every particle of the punya to your father. Naraka cannot hold what Mokshada Ekadashi has claimed.'
The vrat and the jagran of Gita
Vaikhanasa returned and observed the vrat with the entire royal household. From sunrise the king took only Ganga jal; the queen and the ministers all joined the fast. Through the whole day and night the Bhagavad Gita — all eighteen adhyayas — was chanted in the palace assembly, and at every yama of the night the king himself performed tulsi-arghya upon the shalagram, calling his father's name in every sankalp. At Dwadashi's Brahma-muhurta he broke the fast on Ganga-tulsi jal and, folding his hands towards Bhagwan Vishnu, said, 'Whatever punya has come to me from this vrat, I give in totality to my father; let nothing remain for me.'
The liberation of the father
That very night the father appeared once more — but now radiant, clothed in pitambara, garlanded, on a viman of the Vaishnava-dutas. 'Beta, no punya of yajna or of tirtha could have done what this one vrat has done. Naraka has released me. I go to the loka of Bhagwan Vishnu. You have given me the greatest gift a son can give a father — moksha itself.' The king wept in joy. Since that day the shastra declares: read even one adhyaya of the Gita on Mokshada Ekadashi and it equals a full yajna; keep the vrat itself and both the vrati and seven generations of pitrs are lifted to Vaikuntha.
"Grants moksha to the vrati and to seven generations of ancestors. Uniquely permits transfer of the vrat's punya to another soul, living or departed. Reading even one adhyaya of the Bhagavad Gita on this day is declared equal to a full yajna, and reading the whole Gita equal to a hundred ashvamedhas."