  Considering nonforward scattering amplitude off the heavy quark in the Small
Velocity limit two exact superconvergent sum rules are derived. The first sum
rule leads to the lower bound \rho^2 > 3/4 for the slope of the Isgur-Wise
function. It also provides the rationale for the fact that the vector heavy
flavor mesons are heavier than the pseudoscalar ones. A spin-nonsinglet
analogue \bar\Sigma of \bar\Lambda = M_B-m_b is introduced.
