Use the equal-time canonical commutation and anticommutation relations to prove Eq. (8.3.22). Then for either a boson or fermion operator \(\hat{X}(y)\) generalize Eq. (6.2.166) and show that \(\partial_{\mu}^{x}\left\langle\Omega\left|T \hat{j}^{\mu}(x) \hat{X}(y)\right| \Omega\rightangle=\delta\left(x^{0}-y^{0}\right)\left\langle\Omega\left|\left[\hat{j}^{0}(x), \hat{X}(y)\right]\right| \Omega\rightangle\). Then further generalize this result to verify the QED Ward identity in Eq. (8.3.21).