Garudapurana 1.125

The glorious Garuḍa Mahāpurāṇa — 125 / Pitāmaha said: / King Māndhātā became a universal monarch by fasting on the eleventh lunar day. / One should not eat on the eleventh day in either of the two fortnights.

An eleventh lunar day mixed with the tenth was fasted by Gāndhārī; / her hundred sons were lost, therefore one should avoid it.

Where the eleventh day meets the twelfth, there Hari is present; / where the eleventh day meets the tenth, there an asura is present. / When doubt arises through the conflict of many statements,

Then the twelfth lunar day is to be accepted, and breaking the fast takes place on the thirteenth. / Even if the eleventh day lasts for only a minute fraction, the twelfth day is likewise to be fasted.

The eleventh, the twelfth, and especially the thirteenth: / that lunar day combining the three is to be observed as auspicious and destroying all sins.

O twice-born one, fasting on the eleventh day, or on the twelfth, / one should indeed observe the threefold combination, but never [a day] joined with the tenth.

Keeping vigil at night, listening to the Purāṇas, / and worshipping Gadādhara, King Rukmāṅgada attained liberation by fasting on both eleventh days, as did others [by performing] the observance of the eleventh lunar day.

Thus ends the one hundred and twenty-fifth chapter, named 'The Greatness of the Eleventh Lunar Day', in the Ritual Section called the First Part of the First Section of the glorious Garuḍa Mahāpurāṇa.