In the Mahabharata Viraja is the name of the primeval being, Purusha, identified with Vishnu and Shiva(Lord Ayyappa).
[2] Viraja is identified by Atharvaveda – 4.11.7 with Indra, Agni, Prajapati and Parameshtin (A.V.iv.11.7); with Devata, Vishnu, Savitr, Rudra, Brahmachari, Water and the world (A.V.viii.5.10), with controlling Indra (A.V.xi.5.16), with the immortal wide spreading ruling power (A.V.vii.84.1), with first and creative principle (A.V.viii.9.7), with the universe (A.V.viii.10.11), as father of Brahman (A.V.viii.9.7), with speech, the earth, the atmosphere, death (A.V.ix.10.24), with the udder of the frame of creation, Brahman being its mouth (A.V.x.7.19) and with Dhruva, the point of the heavens directly under the feet (A.V.xii.3.11).
[3] The following four verses of Taittiriyopanishad-bhasyavartikam methodically describe Viraja: Viraja, as Deva, as the first-born Fire, the first embodied being (Shiva Purana V.i.8.22), is reminiscence of the Purusha (Rig Veda X.90), in elder Upanishads this name appears thrice – once in the Brihadaranyaka Upanishad passage IV.ii.3 as "the human form that is in the left eye", and twice in the Chandogya Upanishad in passages I.xiii.2 as the stobha called Vak (Vairaj Sama) and IV.iii.8 as the food and as the eater of food, Viraja is food - virad annam bhogyatvad eva (BUBh 4.2.3).
In Vedantasara it is Vaisvanara and is said to be Caitanyam (intelligence) identified by Sthulasariram, Annamayakosha and Jagrad on one hand and on the other it is Hiranyagarbha or Prana, the intelligence conditioned by Suksamasariram consisting of Vijnanamayakosha, Manomayakosha and Pranomayakosha, or Svapna; it is explained this way to systematize these notions.
[4] The gods obtained virajam (brilliance) from Agni by means of consecration, Viraja is the year consisting of twelve months, the fire to be piled is the year, the bricks that are piled are the days and the nights, and Viraja consists of six seasons, and has thirty syllables(Yajur Veda v.6.7).