According to the folklores, when Shri Ram was passing through this route on his way to Lanka, his anger over Ravana were quite evident as his army could see him in his Veer' (brave warrior like) form. The veins of Shri Ram, swelled due to anger, are clearly visible even in the statue installed in this temple.
Valmiki Ramayana full chapters onwards 6/4/9 Manas 5/34/2/ to 5/34/ chhand 2.
