According to Bhāgavatapurāṇa (Bhagavatapurana), Prāṇa(Prana) is one of the Aṣṭavasu (Ashtavasu; the Eight Vasus). Ūrjasvatī (Urjasvati) is the wife of Prāṇa. Three sons, namely, Saha, Āyu (Ayu) and Purojava were born of the womb of Ūrjasvatī, sired by Prāṇa.