"Your Lord is most knowing of you," meaning: of your deeds. He addressed the polytheists with this. "If He wills, He will have mercy upon you," meaning: He will accept your repentance and favor you with Islam, "or if He wills, He will punish you," for your persistence in polytheism. "And We have not sent you over them, O Muhammad, as a manager," meaning: a guardian over their deeds so that He would requite them for them.