It is also called Asddha-sukla Ekadashi. Told by Lord Brahma, There is nothing better than Ekdiasi, the day of Lord Hari. It nullifies even the worst of sins if observed properly.
‘Fasting on this Ekadashi ( Asddha-sukla Ekadashi / Padma Ekadshi ) purifies one of all sins and fulfills all one’s desires.
Lord Shri Krishna also told , Padma Ekadashi is so powerful that one who simply reads or hears its glories becomes completely sinless. one who wishes to please Me should strictly observe this Ekadashi, which is also known as Deva-sayani Ekadashi. whoever wants liberation should regularly observe a fast on this Ekadashi, which is also the day when the Caturmasya fast begins.”