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 God annuls or confirms whatever He wills [of His earlier messages] - for with Him is the source of all revelation. 39 Whether We show thee a part of that We promise them, or We call thee to Us, it is thine only to deliver the Message, and Ours the reckoning. 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 And verily, those before them did devise plots, but all planning is Allah's. He knows what every person earns, and the disbelievers will know who gets the good end (final destination). 42 And those who disbelieve say: You are not a messenger. Say: Allah is sufficient as a witness between me and you and whoever has knowledge of the Book. 43