Myths of Bhrigu
Bhrigu finds mention in Shiva Purana and Vayu Purana. In the Bhagavad Gita, Lord Krishna says that among all the sages, Bhrigu is representative of the magnificence of God. The great works of Bhrigu can be found in Muir's Original Sanskrit Texts. King Nahusha tormented over the Brahmans and compelled the Rishis to carry him from one place to another. Bhrigu then asked Agastya why they submit to the insults of this king. To this, Agastya answered that none of the Rishis had risked cursing Nahusha because he had obtained the power of restraining to his service every one upon whom he fixed his eyes.
However, Agastya said that he was prepared to do anything that Bhrigu might suggest. Bhrigu said that he had been sent by Brahma to take revenge on Nahusha. The king was about to attach Agastya to scorn him with his foot. Then Bhrigu incensed at this insult cursed Nahusha to become a serpent. This happened accordingly. Bhrigu's Ashram 'Deepotsak' was situated near Dhosi Hill in Narnaul district in Haryana, from where he migrated to Bharuch. When a big Yagna was designed and the question of deciding who among the Trinity of Brahma, Vishnu and Shiva should be considered as the best and made the Chief of the Yagna, all the sages requested Bhrigu to make a decision. Bhrigu declared Vishnu as the best.
Cursing of Vishnu
When the fight developed between the Devatas and the Daityas, the Devatas led by Indra had the higher hand. Daityas went to their Guru, Sukracharya and wanted his help. Then he left for harsh Tapas (penance) to please Lord Shiva and get the Mantra Siddhi. During his absence, the Daityas sought refuge in Usana, the mother of Shukracharya. She promised them the security and she came out of her cottage using her powers to freeze the Devatas. Once they became motionless, they became simple targets for the Daityas. The Devatas prayed to Lord Vishnu to protect them and get them out of the predicament. Vishnu understood that the curse on Devatas could not be cancelled unless Usana was killed. But Usana, being a lady was not to be killed as per dharma.
Vishnu covered himself as a brutal beast and tried to scare Usana. Usana saw through the cover of Vishnu and said to Him: “Vishnu, I am doing my responsibility of protecting my children and you are supposed to be neutral and protect dharma. You have now become biased and this Adharma cannot be left scot-free. I am going to curse you. You and Indra will be reduced to ash!” Before these words were spelt out, Vishnu killed Bhrigu’s wife with a sharp arrow and separated her head from the upper body. Once Usana was killed, her powers also left and Devatas became free. Sage Bhrigu cursed Vishnu to take birth on earth and go through the cycles of birth and death and thus suffer like us. He brought his wife back to life with his powers. Vishnu accepted the curse of the sage as he accepted the curse of Sage Durvasa.