King Ambarisha was a great devotee of Vishnu who adhered firmly to the truth. He performed a Yagnya with such great devotional fervour that Narayana was pleased to bless him with his Sudarshana Chakra as a shield of protection over him.
Once, Ambarisha performed a religious rite known as the Ekadashi and Dvadashi Vrata, for 1 year (i.e. the king would fast on the 11th day of every lunar month, and break his fast the next day). After observing this practice for a year, he took up a final fast of 3 days and nights to conclude the rite. As the moment for breaking this fast drew near, sage Durvasa arrived where Ambarisha was and the king received him with due respect. Durvasa agreed to the king’s request to be his honoured guest, and asked the king to wait until he had finished his bath in the river Yamuna. The auspicious moment soon arrived when the king had to break his fast to fulfill his vow, but Durvasa had not yet returned from his bath. Ambarisha was in a dilemma, as, on the one hand, it was impolite to take food before serving a guest, but on the other, the time had come for the fast to be broken. After consulting his priests, the king broke his fast by taking a sip of water, and awaited Durvasa’s arrival to offer him food.
Durvasa felt that Ambarisha had violated the respect due to a guest by breaking his fast before the guest had taken his meal, and in his rage created a demon to kill Ambarisha, out of a strand of his hair.
Narayana’s Sudarshana Chakra intervened, destroyed the demon and started chasing Durvasa himself.
Durvasa went to Brahma and Shiva for protection. Both pleaded their inability to save him from the Sudarshan Cakra of Supreme Personality of Godhead, Lord Vishnu. Durvasa next went to Narayana himself, who said that he could do nothing as he was bound by the blemishless devotion of Ambarisha and suggested that the sage seek the king’s pardon. Durvasa took this advice and returned to Ambarisha, who prayed to Vishnu to recall the Sudarshana and save the sage, whereby the discus ceased to afflict him.