And they ask you (O Muhammad SAW) concerning the Ruh (the Spirit); Say: "The Ruh (the Spirit): it is one of the things, the knowledge of which is only with my Lord. And of knowledge, you (mankind) have been given only a little." 85 If We willed, We could take away that We have revealed to thee, then thou wouldst find none thereover to guard thee against Us, 86 Unless your Lord have mercy. His blessings on you are great indeed. 87 Say: "If all mankind and all invisible beings would come together with a view to producing the like of this Qur'an, they could not produce its like even though they were to exert all their strength in aiding one another!" 88 We have indeed turned about for men in this Koran every manner of similitude; yet most men refuse all but unbelief. 89 They said: "We shall not accept your Message until you cause a spring to gush forth for us from the earth; 90 or till thou possessest a garden of plants and vines, and thou makest rivers to gush forth abundantly all amongst it, 91 or cause the sky to fall into pieces on us - as you believe you can - or bring God and the angels face to face with us, 92 Or you have a house of gold or you ascend into the sky. And [even then], we will not believe in your ascension until you bring down to us a book we may read." Say, "Exalted is my Lord! Was I ever but a human messenger?" 93