Devshayani Ekadashi - the Ekadashi that falls on the eleventh day of the month - is seen as one of the most auspicious Ekadashis of the year. Every Ekadashi is dedicated to Lord Vishnu. But this Ekadashi holds more significance because it is believed that Lord Vishnu goes to sleep on this day and that too for a period of four months.
This period is known as Chatur Masa. Devshayani is a Sanskrit word meaning, when god sleeps and, similarly, Chatur Masa means a period of four months.
Devshayani Ekadashi is observed as a fasting day. Though the fast is observed as other Ekadashi fasts, the only difference is that on this day, the idol of Lord Vishnu is made to sleep in a white bedding. As of other rituals, the devotees should get up early, take bath during the Brahma Muhurta time.
Prayers are offered before the idol of Lord Vishnu. After offering dhoop and deep to the Lord, the devotees should narrate the story of Devshayani Ekadashi.
Once Dharma Raj Yudhishtir asked Lord Krishna what is the significance and the procedure to perform Devshayani Ekadashi, to which Lord Krishna replied, "Hey Yudhishtir, let me explain to you the story which Lord Brahma had narrated to Narad Muni."
He had told Narad Muni that those who observe this fast get all the past sins, which they have committed by mistake, washed away. It is a must for everyone to observe this fast. Performing puja and observing a fast on this day pleases Lord Vishnu.
It is also known as the Vishnu Shayani Ekadashi day, or the Harishayani Ekadashi, or the Ashadha Ekadashi. There goes a mythological story behind this, which is as follows.
There was a king by the name Madhanta, who was a righteous man. A generous king, he used to serve the people of his kingdom just as a father would look after his child. The kingdom was rich and prosperous.
Once it so happened that there was no rainfall for three years. This lead to a famine in the kingdom and, gradually, all the stocks of the food grains vanished. The common men in the kingdom became poor as well as fell a victim to starvation.
As the king came to know about this, through his men, he consoled the people and said that soon a remedy would be found for this. Along with some men, the king went towards a forest. In the forest, he headed towards the cottages where the sages lived.
Among the sages, was a sage named Angira Rishi. He bowed down before the sages. And then explained the whole story before Angira Rishi. The king said he knew that the kingdom suffered because of the misdeeds of the king himself.
However, as he had been a righteous man, he said that his kingdom should not have suffered from famine. Upon which the sage said that the Satyuga is the best of all the Yugas that mankind is divided into. Only the Brahmins can read the Vedas, in this Yuga; people worship Lord Brahma.
However, the sage went on to say that in his kingdom, there was a Shudra who'd been worshipping Lord Vishnu without properly cleansing himself. In Satyuga, only the Brahmins could perform Vishnu worship.
The sage said that the sufferings of the people will be removed only when that Shudra stopped worshipping Lord Vishnu, to which the Lord himself replied that he had no right to stop a man from the almighty. Everybody can offer prayers to the one who is the father of all.
Now, the king asked for another remedy. The sage this time advised the king to observe the fast of Ashadha Ekadashi, which falls on the eleventh day of the Shukla Paksha. This fast is the giver of all the powers and achievements, as well as it cleanses the sins of the devotees.
He asked the king along with his kingmen, servants as well as the ministers to observe this Ekadashi. The king agreed to this and thanked the sage. As he returned, he declared that the whole kingdom must perform the Ashadha Ekadashi fast. Because of the devotion of the whole kingdom, Lord Vishnu was pleased, and soon the plight of the people vanished.