An artistic take on the events found in the book of Isaiah when the phrophet was caught up in a vision and caught of glimpse of the seraphim angels praising the Lord.  
 
"Above him stood the seraphim.  Each had six wings: with two he covered his face, and with two he covered his feet, and with two he flew.  And one called to another and said
   "'Holy, holy, holy is the Lord of hosts;
      the whole earth is full of His glory!"'
 
-Isaiah 6:2-3 (NIV)