  We present an analytical calculation of additional real or virtual radiation
of the light fermion pair in the fermionic decay of the Higgs boson $ H \to
f_1\bar f_1$ for arbitrary ratios of the Higgs boson mass to the $f_1$ fermion
mass.
  This result gives us a value of the $O(N_f \alpha _s^2)$ radiative correction
to the inclusive decay rate $ H \to f_1\bar f_1$. Using this result in the
framework of the Brodsky-Mackenzie-Lepage scheme, we discuss the scale setting
in the one-loop QCD correction to the decay width $ H \to f_1\bar f_1$ for
arbitrary relation between the Higgs boson and fermion masses.
