King Abareesh was a great devotee of Lord Vishnu. He was regularly fasting on ekadashi. Ekadashi fast is completed by a having a meal early before dwadashi tithi ends. If one fails to eat on dwadashi he loses the punya of Ekadashi. Once to test Ambareesh , Sage Durwasa came in the early hours of Dwadashi to Ambareesh. He offered to complete the fast along with Ambareesh and went for a bath . As dwadashi was nearing an end , Durvasa muni was not to be seen , King grew anxious , just as one second was left King ambaresh took the Teertha of Hari to complete his vrata , without offering anything to Sage Durvasa who, just appeared after the consumption of teertha. Sage grew very angry and said King had faulted on Athithi satkara by having food even before the athithi. King replied having drunk water is still considered to be in the state of upavasa only. and at the same time it can also be considered as having eaten by Dwadashi time to complete vrata. So he has not done any sin. Sage grew red in anger and plucked his hair , threw it on the ground to create a dangereous demon , to kill Ambareesh. Demon proceeded to kill Ambareesh , Ambareesh meditated on Lord Vishnu, Vishnu pleased with his Vrata nistha of Dwadashi , sent his Sudarshna chakra which protected KIng from Demon (Kritya) of Durvasa. And then it chased Durvasa till the end of tye universe. Durvasa fearing for the Life prayed Lord Vishnu for forgiveness, Lord asked Durvasa to beg forgivance to Ambareesh , Ambareesh relieved Durvasa off the heat of Sudarshana Chakra . Thus Ambareesh , though ordinary before Durvasa could stand tough because of his Vrata. Troubling Vishnu bhaktas is never tolerated by VIshnu , he instantly comes to their help , whoever the opponent be, however powerful the opponent be, Dwadashi vrata protects from all.
Na vasudeva Bhaktanam ashubham vidyate Kwachit