"And if not that a disaster should strike them"—meaning: punishment—"for what their hands have put forth"—that is, due to what they are upon of polytheism—"and they would say, 'Our Lord, why did You not send to us a messenger?'" The verse means: And had We punished them, they would have argued, saying: "Our Lord, why"—meaning: why did You not—"send to us a messenger so that we might follow Your verses and be among the believers?" Thus, Allah severed their excuse with Muhammad, yet they denied him. Allah said: