۞ Say: What! do you indeed disbelieve in Him Who created the earth in two periods, and do you set up equals with Him? That is the Lord of the Worlds. 9 He placed therein (i.e. the earth) firm mountains from above it, and He blessed it, and measured therein its sustenance (for its dwellers) in four Days equal (i.e. all these four 'days' were equal in the length of time), for all those who ask (about its creation). 10 Then He turned to heaven when it was vapour and said to it and to the earth, "Come willingly or unwillingly." They both said, "We come willingly," 11 Then He created several skies in two spans, and ingrained in each sky its function, decking the nearest heaven with lamps, and guarded it. This has been determined by the mighty and all-knowing. 12 Then if they Still turn away, say thou; I warn you of a calamity like the calamity of the 'Aad and Thamud. 13 When their apostles came to them from before them and from behind them, saying, Serve nothing but Allah, they said: If our Lord had pleased He would certainly have sent down angels, so we are surely unbelievers in that with which you are sent. 14 As for Ad, they waxed proud in the earth without right, and they said, 'Who is stronger than we in might?' What, did they not see that God, who created them, was stronger than they in might? And they denied Our signs. 15 So We sent against them a furious Wind through days of disaster, that We might give them a taste of a Penalty of humiliation in this life; but the Penalty of a Hereafter will be more humiliating still: and they will find no help. 16 And as for Thamud, We guided them, but they preferred blindness over guidance, so the thunderbolt of humiliating punishment seized them for what they used to earn. 17 And We delivered those who believed and used to keep their duty to Allah. 18