Vāruṭhinī Ekādaśī 2167

When Yudhishthira asked about the Ekadashi of the dark fortnight that follows Chaitra Purnima, Sri Krishna named it Varuthini, the protecting one, and described its glory.

He said that this fast brings good fortune in this world and the next and burns away accumulated sins. The great kings of the solar line, Mandhata and Dhundhumara, are remembered as having attained the higher worlds by observing it. Krishna compared its merit to the greatest gifts known: gifts of land, of gold, of grain, and the righteous giving of a daughter in marriage, and declared that Varuthini equals or surpasses them.

The observer keeps the Dashami with restraint, fasts and stays awake in worship on Ekadashi, and breaks the fast on Dvadashi. Merely hearing this account is said to bring the merit of giving a thousand cows.