  It turns out that the infinite derivative gravity (IDG) is ghost-free and
renormalizable when one chooses the exponential of an entire function. For this
IDG case, the corresponding Newtonian potential generated from the delta
function is non-singular at the origin. However, we will explicitly show that
the source generating this non-singular potential is given not by the
delta-function due to the point-like source of mass, but by the Gaussian mass
distribution. This explains clearly why the IDG with the exponential of an
entire function yields the finite potential at the origin.
