21 Bhagavatha -- Atri and Anasuya

Atri is one of the saptarishis. He is believed to be the manasaputra of Brahma. (Atri, meaning one who is
free from the three gunas, emerged from the eyes of Brahma). His wife is Anasuya, daughter of Kardama Prajapati (Anasuya - free from jealousy). 
Atri's austerities were legend. It is said that when he controlled his breath through pranayama, smoke emanated from his head.
Anasuya was an embodiment of chastity. Once, in order to glorify her chastity to the world, Brahma, Vishnu and Siva visit Anasuya's ashram as Brahmins and seek bhiksha (for food) with the condition that she should serve it without any clothes on. Anasuya without any hesitation agrees. She invokes her devotion to her husband and sprinkles some water on her divine guests, who become small babies. The trio blessed them with three sons, Datta (a manifestation of the three forms of the Lord, Brahma, Vishnu and Siva), Sage Durvasa (one who was free from vasana), and Soma (the moon god).