  Recently, a new assumption was proposed in [Phys. Rev. D 100, no.10, 104022
(2019)]. This assumption considers that the energy of the particle changes the
enthalpy of the black hole after throwing the particle into the black hole.
Using the energy-momentum relation, the results show that the second law of
thermodynamics of the black hole is valid in extended phase space. In this
paper, we discuss the validity of the laws of thermodynamics and the stability
of the horizon of the charged AdS black hole by scalar field scattering under
two assumptions, i.e., the energy flux of the scalar field $dE$ changes the
internal energy of the black hole $dU$ and the energy flux of the scalar field
$dE$ changes the enthalpy of the black hole $dM$.
