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 Had We willed, We could take away what We have revealed to you, then you would find none to help you in recovering it from Us. 86 excepting by some mercy of thy Lord; surly His favour to thee is great. 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 say: 'We will not believe in you until you make a spring gush from the earth for us, 90 or, until you own a garden of palms and vines and cause rivers to gush forth with abundant water in them; 91 "Or thou cause the sky to fall in pieces, as thou sayest (will happen), against us; or thou bring Allah and the angels before (us) face to face: 92 Or thou have a house of gold; or thou ascend up into heaven, and even then we will put no faith in thine ascension till thou bring down for us a book that we can read. Say (O Muhammad): My Lord be Glorified! Am I aught save a mortal messenger? 93