Chanting Vishnu’s name and worshipping Lord Shri Vishnu’s Padmanabha form with belief should be done on this day. It is said that the merit of this fast is similar to that of Surya Yagya and penance (tapa). Keeping a day-long fast, chanting Shri Hari Vishnu’s name and His shlokas is a common practice during Ekadashi. The merit of this particular Ekadashi is known to eradicate one’s past-life sins. Stories of Ekadashi were told by Shri Krishna to Yudhishtir and Arjun.
The story of Papankusha Ekadashi goes as: Once upon a time, there lived an evil-doer named Krodhan on the Vindhya Mountain. That fowler was very cruel, insidious, and always involved in deceit. When his death time approached, Yamraj asked his messengers to kill the evil fowler and bring his soul to yamloka. After this, the Doots of Yamraj went to him and said,” tomorrow is going to be the last day of your life. We will come to pick you up tomorrow.” Upon hearing the news of his death, the fowler got scared and ran to Maharishi Angira. As the fowler reached Maharishi’s ashram and saw him, the fowler fell at his feet and started praying. He said, “O sage! I have committed various sins my whole life. Please tell me a remedy, by which all my sins can be erased and I can attain salvation.” At his request, Maharishi Angira advised him to observe fast on Papankusha Ekadashi of Shukla Paksha of Ashwin month. As said by Maharishi Angira, the fowler performed this fast and rituals. He got rid of all the sins committed and by the Punya of observing this fast and by the blessing of Shri Hari, he went to Vishnu Lok. When the Doots of Yamraj saw this, they returned to Yamlok without the fowler.
Hence, it is believed that by observing this particular fast with a sincere heart, one gets rid of all the sins committed intentionally and unintentionally. The observer gains the blessings of Lord Vishnu and receives prosperity, wealth, and luck. The Punya of this Ekadashi helps one live a peaceful life and attain moksha after death.