  We consider an obstacle problem in the Heisenberg group framework, and we
prove that the operator on the obstacle bounds pointwise the operator on the
solution. More explicitly, if $\epsilon\ge0$ and $\bar u_\epsilon$ minimizes
the functional $$ \int_\Omega(\epsilon+|\nabla_{\H^n}u|^2)^{p/2}$$ among the
functions with prescribed Dirichlet boundary condition that stay below a smooth
obstacle $\psi$, then 0 \le \div_{\H^n}\, \Big((\epsilon+|\nabla_{\H^n}\bar
u_\epsilon|^2)^{(p/2)-1} \nabla_{\H^n}\bar u_\epsilon\Big) \qquad \le
(\div_{\H^n}\, \Big((\epsilon+|\nabla_{\H^n}\psi|^2)^{(p/2)-1}
\nabla_{\H^n}\psi\Big))^+.
