Once there lived a virtuous king by name Ambarisha. Being an ardent devotee of Lord Vishnu, he used to observe Ekadashi Vrata. Ekadashi falls on the eleventh day of every lunar fortnight. Once, sage Durvasa known for his anger visited the king on Dwadashi, the next day of Ekadashi. The devotee ends the vrata by having some food on Dwadashi. Pleased with the arrival of the sage, Ambarisha requested him to partake food.
Durvasa accepted the invitation but he wanted to bathe and perform pooja before having food. The Dwadashi period was about to end, but the sage did not turn up. As part of the vrata, Ambarisha had to have some food during Dwadashi itself. He was in a dilemma. So after deliberating with the scholars in the court, he took Tulasi teertha only to mark the end of the vrata.
Sage Durvasa who was returning just then, found Ambarisha having some water and he felt slighted. A host had not waited for the guest. He cursed Ambarisha to have ten incarnations (Dashavatharas) on the earth. In order to protect His devotee, Lord invited the curse upon Himself. His Dashavataras include Matsya, Kurma, Varaha, Narasimha, Vamana, Parashurama, Rama, Krishna, Buddha and Kalki.
Lord Vishnu released his Sudarshana Chakra on Durvasa. Durvasa ran to all gods for protection, but none could help him. Finally, he went to Lord Vishnu. Lord Vishnu suggested Durvasa to go to Ambarisha, as He Himself did not have any control over the weapon which was out to protect His devotee. So Durvasa apologised to Ambarisha. The Chakra returned upon Ambarisha’s plea to the Lord and the Chakra.