Ambarisha in Hindu mythology, was an Ikshvaku king and son of Nabhaga.He was a great devotee of Vishnu and adhered firmly to the truth. He performed a yaga with such great devotional fervour that Lord Narayana was pleased to bless him with Sudarshana Chakra.
There was a king named Ambarisha who was very kind and noble to all his subjects and he did a lot of charity. Though he was loaded with wealth and richness, he never cared much for them. Ambarisha had never been a prey for worldly pleasures and money for he was aware that these enjoyments never lasted for a long time and he strongly believed that only those people who are lacking knowledge and who don't feel the presence of god, get excited and go behind these unwanted things in life. He was a great devotee of Sri Narayana and one can even challenge, for if ever the Lord had an ardent devotee it would be only Ambarisha. His mind was always thinking of the lotus feet of Sri Vishnu and kept chanting his praisings and mantras. Wherever he went and whatever he did, Ambarisha was reminded of the divine presence of the Lord Narayana and he was able to view only expressions of divinity. Since he was always dedicated to Lord Narayana and his thoughts, Ambarisha soon gave up all his desires in life. Sri Vishnu was very pleased with him and gave him his chakra for his protection and the King was very happy about it. Once, King Ambarisha and his wife undertook a special fast called the Dvadasi Vrata, which requires special disciplines to be followed. The Dvadasi Vrata has to be followed for one whole year where towards the end he has to fast for three continuous days. After this on the fourth day, which is the twelfth day of the moon he can go ahead and break the fast.
Ambarisha followed the vrata very piously for one whole year and on that particular day of the occasion he went to the temple of Narayana at Mathura and had a holy dip in the river Yamuna. As a part of charity he distributed lot of gifts and cattles to the poor and needy. During this time the great Rishi Durvasa came to Mathura and met Ambarisha. So the King told him about his Dvadasi Vrata and requested the rishi to be his guest for the day. Durvasa rishi also obliged to the King's request and invitation and then went to the river to bathe and to perform his daily rites. After having a bath in the holy water and when Durvasa sat for his meditation he got himself deep into it and was lost from the world for a while. Ambarisha was getting very worried if he is going to miss the auspicious time to perform the rites and pooja, for if he misses the vrata it goes off vain and it avails no power. Ambarisha was in a dilemma for he cannot break his fast with the rishi which will be a great insult to Durvasa. Being invited and if due respect is not given, the powerful rishi Durvasa might get angry. So the king decided to compromise by sipping a little water which the sastras say is both eating and non- eating. Thus now the king was happy for he didn't miss the right time to complete his vrata nor did he mean any offence to the great sage.
When Durvasa finished his meditation and came to the spot, he realized what had happened, he felt very insulted thinking that Ambarisha has done this out of pride. Durvasa got very angry and he tore a tuft of hair and made it to become a demon. Now he cursed the king by asking the demon to kill him. But the king did not react to all this instead remained calm with no fear for the chakra given by Lord Narayana came to the protection of the king. The chakra also progressed in the direction towards Durvasa and the demon also lost all his power. Now the great rishi did not know what to do and to save his life he ran to Brahma and Lord Shiva. But unfortunately they told him that he had been very harsh to a Vishnu Bhakthan and they are helpless. Durvasa tried all his means to escape from the chakra but he could do nothing. Finally he ran and appealed to Sri Vishnu for help. Lord Vishnu told Durvasa, that he is a slave to all his devotees and he cannot forsake them at the time of their requirement. He suggested to the rishi that there is only one way to escape from the chakra and that is to run back to the person whom the rishi has offended and to beg his pardon. Thus Durvasa went back immediately to Ambarisha and apologized and the king made the chakra stop from destructing the rishi. Later Ambarisha made his eldest to rule over the Kingdom and took off to the forest to plunge his mind into meditation upon the Lord.