According to the Pancharatrastavam of Vaishnavism, for the Vasudeva Chaturmurti there are four main primary aspects namely, Vasudeva, Sankarshana (Lion), Pradyumna (Boar) and Aniruddha. The four faces of Lord Vishnu mentioned in the Vishnu Dharmottara passages are taken to stand for the above four Vyuhas. Thus the Narasimha type of manifestation is an important vyuha of the Lord. It is stated in the Nrisimha Purvthapani Upanishad that God appeared before Brahma as Narasimha first, and gave him the mantra viz., the Narasimha Anushtup, with which he was able to develop the four Vedas later. The Anushtup is as follows:
ॐ उग्रं वीरं महाविष्णुं ज्वलन्तं सर्वतोमुखम्
नृसिंहं भीषणं भद्रं मृत्योर्मृत्युं नमाम्यहम् ||
In the above Anushtup, there are nine forms of Narasimhaswamy with a number of faces, the Narasimha or the ordinary Narasimha, the Bhishana or the frightful, the Bhadra or the terrible and the Mrityormrityu or the killer of death.
It is of interest to note that no Yantrapratishtha can be complete without this Narasimha Anushtup engraved upon it. Thus this is the very basis for all yantras. It is also interesting to see that Arjuna's prayer when he saw Lord Krishna in his Viswaroopa in the Bhagvatgita seems to be more or less in relation of the various words, Ugra, Veera etc., in the same sequence as in mantra above. A close study of the shlokas twenty to thirty one of the chapter II of Bhagavatgita reveals a direct connection between them and the mantra starting from Ugra and ending with Namamyaham.
Thus it will be seen that the Upanishadas, the Divyaprabandhams, and the Gita all mention the greatness of Narsimha Mantra.
