The static-source model is generalized to allow for the recoils and the mutual degrees of freedom of the source'' particles by adding to the Hamiltonian corresponding to the field and its sources the nonrelativistic Hamiltonian for the motion of the heavier particles. The resulting system can be quantized. The scattering of mesons by nucleons and deuterons is calculated using the interaction of the pair theory in first approximation. The description of the deuteron is effected by a system of functions containing one bound state only. (auth)