When Lord Brahmā ordered Atri Muni to create generations after marrying Anasūyā, Atri Muni and his wife went to perform severe austerities in the valley of the mountain known as Ṛkṣa.... He was thinking: "May the Lord of the universe, of whom I have taken shelter, kindly be pleased to offer me a son exactly like Him." While Atri Muni was engaged in these severe austerities, a blazing fire came out of his head by virtue of his breathing exercise, and that fire was seen by the three principal deities of the three worlds. At that time, the three deities approached the hermitage of Atri Muni, accompanied by the denizens of the heavenly planets, such as the celestial beauties, the Gandharvas, the Siddhas, the Vidyādharas and the Nāgas....
The three deities told Atri Muni: "Dear brāhmaṇa, you are perfect in your determination, and therefore as you have decided, so it will happen; it will not happen otherwise.... You will have sons who will represent a partial manifestation of our potency, and because we desire all good fortune for you, those sons will glorify your reputation throughout the world." Thus, while the couple looked on, the three deities Brahmā, Viṣṇu and Maheśvara disappeared from that place after bestowing upon Atri Muni the benediction. Thereafter, from the partial representation of Brahmā, the moon-god was born of them; from the partial representation of Viṣṇu, the great mystic Dattātreya was born; and from the partial representation of Śaṅkara [Lord Śiva], Durvāsā was born.
Anusuya said: - "If the celestials headed by Brahma are propitiated with me and are prepared to give me a boon and If am deemed by you worthy of it, then let Brahma, Vishnu and Maheswara be born as my sons; and may I with my husband acquire Yoga leading to the liberation from miseries." Thereupon, Brahma, Vishnu, Siva, and other gods said "so be it". Then honouring that female ascetic they repaired to their respective habitations.
Thereupon after a long time Brahma's son the divine Atri cast his look upon his own wife Anusua; bathed after her course having all her limbs purified and an excellent form worthy of being coveted by all. Having his mind stricken with desire that ascetic thought in his mind of that one of a blameless person.... The moon, the stay of the life of all creatures, was born as the mind begotten son of the patriarch Atri. Well-pleased the high-souled Vishnu was born from his own body as the best of the twice-born, Dattatreya permeated by the quality of goodness. Incarnating himself Vishnu was born as the second son of Atri known under the name of Dattatreya who sucked the breast of Anusuya.... Then was born Durvasa, a portion of Rudra impregnated with the quality of darkness. Thus Brahma, Vishnu, and Siva were born as her three sons. By virtue of the boon conferred upon her by the celestials Brahma was born at the moon, Vishnu as Dattatreya and Sankara as Durvasa."
