Anasūyā, the wife of Atri Muni, gave birth to three very famous sons — Soma, Dattātreya and Durvāsā — who were partial representations of Lord Viṣṇu, Lord Śiva and Lord Brahmā. Soma was a partial representation of Lord Brahmā, Dattātreya was a partial representation of Lord Viṣṇu, and Durvāsā was a partial representation of Lord Śiva.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
अत्रेः पत्न्यनसूया त्रीञ्जज्ञे सुयशसः सुतान् । दत्तं दुर्वाससं सोममात्मेशब्रह्मसम्भवान्
atreḥ patnyanasūyā trīñjajñe suyaśasaḥ sutān | dattaṃ durvāsasaṃ somamātmeśabrahmasambhavān
SB 4.1.15