And We sent Messengers before thee, and We assigned to them wives, and seed; and it was not for any Messengers to bring a sign, but by God's leave. Every term has a Book. 38 Allah effaces whatever He wills and retains whatever He wills. With Him is the Mother of the Book. 39 Whether We allow you to see (the punishment) We have promised them, or end your life before (its execution), it is certainly for you to convey the message; the reckoning is for Us to do. 40 Do they not see Us advancing from all sides into their land and reducing its frontiers? It is for God to judge; and there is none to reverse His judgement. He is swift at reckoning. 41 Now those who lived before these [sinners] did, too, devise many a blasphemy - but the most subtle devising is that of God, who knows what each human being deserves: and the deniers of the truth will [in time] come to know to whom the future belongs. 42 The unbelievers say, 'Thou art not an Envoy.' Say: 'God suffices as a witness between me and you, and whosoever possesses knowledge of the Book.' 43