  We study the heavy quark mass dependence of selected observables constructed
from heavy-light meson correlation functions in small-volume two-flavour
lattice QCD after taking the continuum limit. The light quark mass is tuned to
zero, whereas the range of available heavy quark masses $m_h$ covers a region
extending from around the charm to beyond the bottom quark mass scale. This
allows entering the asymptotic mass-scaling regime as $1/m_h \to 0$ and
performing well-controlled extrapolations to the infinite-mass limit. Our
results are then compared to predictions obtained in the static limit of
continuum Heavy Quark Effective Theory (HQET), in order to verify
non-perturbatively that HQET is an effective theory of QCD. While in general we
observe a nice agreement at the few-% level, we find it to be less convincing
for the small-volume pseudoscalar decay constant when perturbative matching is
involved.
