Significance and legend
Varutha means armour, and Krishna tells Yudhishthira in the Bhavishyottara Purana that this Ekadashi protects its observer from all harm. The story told is of King Mandhata, a righteous ruler on the banks of the Narmada. While he was absorbed in austerity in the forest, a wild bear attacked him and began to drag him away, chewing on his foot. The king, remaining true to his vow of non-violence, did not fight back but called on Vishnu for help. The Lord appeared and slew the bear with his Sudarshana discus, but the king's foot had been lost.
Vishnu consoled him and instructed him to go to Mathura and observe Varuthini Ekadashi, worshipping the Lord's Varaha avatara. He explained that the injury was the result of past karma. Mandhata kept the fast faithfully, and by its power his limb was restored and his body became whole and radiant. The text adds that the merit of Varuthini equals that of giving great gifts of gold and grain, and that it grants both prosperity in this world and liberation hereafter.
How Varuthini Ekadashi is observed
On Dashami one eats a light single meal and avoids certain foods such as lentils, honey and bell-metal utensils, according to traditional rules. On Ekadashi devotees fast, worship Vishnu, especially in his Varaha form, with tulsi and yellow flowers, and spend the day in prayer, scripture reading and charity, avoiding gambling, anger and gossip. Night vigil is recommended. Parana is done on Dwadashi morning after sunrise within the prescribed window, after offering food to Vishnu and giving to a Brahmin or the needy.