Ekadashi means an eleventh lunar day of the fortnight and today significantly is Nirjala Ekadashi. The day is dedicated to worshipping Lord Vishnu. It is believed that out of all the 24 Ekadashis, Nirjala Ekadashi (without water) is the most significant one.
Nirjala Ekadashi is also known as Bhima Ekadashi or Pandava Nirjala Ekadashi.
Bhim-the strongest of the Pandavas, cannot survive with hunger and got annoyed himself for the disrespect shown towards Lord Vishnu. Due to this he sought solution from Maharishi Vyas, who then asked Bhim to start observing Nirjala Ekadashi. He was told that by fasting on this particular day, he would derive the benefits of all the other Ekadashis.
“O Bhima, Lord Sri Krsna has said that whoever observes this Ekadasi should take a holy bath, give charity to a worthy person, chant the Lord’s holy names on a japa-mala, and perform some kind of recommended sacrifice, for by doing these things on this day one receives imperishable benefits. There is no need to perform any other kind of religious duty. Observance of this Ekadasi fast alone promotes one to the supreme abode of Sri Visnu. O best of the Kurus, if one donates gold, cloth, or anything else on this day, the merit one obtains is imperishable,” said Ved Vyasadeva.
Vyasadeva explained to Bhima, “I strongly urge you to fast on this auspicious, purifying, sin-devouring Dvadashi in just the way I have outlined. Thus you will be completely freed of all sins and reach the supreme abode.”
Thus came into existence of Nirjala Ekadashi.
Devotees generally fast on all 24 Ekadashis, however on Nirjala (without water) Ekadashi, people observe fast and do not even consume a drop of water. Those devotees, who are unable to observe the other Ekadashis can observe ‘vrat’ only on this day.
Devotees keep chanting, praying, performs puja for Lord Vishnu the whole night.