Since, 
, we can write
.......................................(2.94)
Using the vector identity,
, we can write
................(2.95)
In the expression 
, for point charges, since V varies as 
and D varies as 
, the term V
varies as 
while the area varies as r2. Hence the integral term varies at least as and the as surface becomes large (i.e. 
) the integral term tends to zero.