And verily We sent messengers (to mankind) before thee, and We appointed for them wives and offspring, and it was not (given) to any messenger that he should bring a portent save by Allah's leave. For everything there is a time prescribed. 38 God annuls or confirms whatever He wills [of His earlier messages] - for with Him is the source of all revelation. 39 BUT WHETHER We let thee see [in thy lifetime, O Prophet, the fulfilment of] some of what We have promised them, or whether We cause thee to die [before its fulfilment] - thy duty is no more than to deliver the message; and the reckoning is Ours. 40 See they not that We gradually reduce the land (in their control) from its outlying borders? (Where) Allah commands, there is none to put back His Command: and He is swift in calling to account. 41 Those who have gone before them devised, but to Allah is the devising altogether. He knows what every soul earns. The unbelievers shall know without doubt for whom is the Ultimate Abode. 42 The unbelievers claim that you have not been sent by Allah. Tell them: "Allah is sufficient as a witness between me and you; and so also do those who know the Scriptures." 43