On what basis is your boast

Story Play (Attakkatha): 
On what basis is your boast that
you are one of the best, you fool?
If you fight me here I will crush
your arrogance in half a second
In due course I will despatch you
as a guest to the God of Death’s abode
Go there and happily narrate to them
the saga of my fighting prowess
Don’t get angry, fight me now and
get to know the strength of my arms