What is the source of Higgs field? Could you please explain me this question. 
As we know that every field has a source like electric field has electric charge and magnetic field has magnet etc. So what is the source of the Higgs field?
 A: The Higgs  particle is an elementary particle in the standard model of particle physics

All elementary particles have a meaning in the quantum mechanical framework, not the classical that you are discussing.
In quantum field theory, every particle in the table above is a quantized field which covers all spacetime. Creation and annihilation operators define the sources , for example a creation operator creates an electron, acting on the electron field,  or a Higgs particle creation operator acting on the Higgs field creates a Higgs meson.
A: Good question. The Lagrangian  of the Standard Model of physics is constructed in such a way that the standard answer to your question is: the Higgs field itself. This is because it contains a huge self-interaction term $\lambda\phi^4$ that causes the ground state of the Higgs to correspond to a constant nonzero value. However, the existence of such a term has not yet been established experimentally and there are other possible explanations for the Higgs vacuum expectation value (which definitely IS established) that do not involve self-interaction.
