Vishnu sahasranamam, slok52

Slok52:        Gabhasthinemihi  Sathvasthaha  Simho  Bhutha Maheswaraha
                       ADiDevo  MahADevo  Deveso  DevabhruDguruhu

The Sun,;  the devine, existing in living beings, the NarasimhAvatar,   the Lord of living beings,  the Prime lord, the Great Supreme  Lord, the Lord of lords, the Guiding Master of GODS,  is Sree Vishnu.  

Vishnu  is the Lord of  all beings; in and out of all beings existing in the
Universe; vishnu is present as Sun, guiding the celestial spiritual entities.
Sun is the " Visible Vishnu". Sun gives vigour and health to all living being. 

Two perticular names, "Sun and Narasimha "are powerful projections of Vishnu.

 Vishnu is "God of god's". The creator of god's, guide of god's, and the commander of gods.

Om Vishnave namaha