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 And if We willed, We could surely do away with that which We revealed to you. Then you would not find for yourself concerning it an advocate against Us. 86 (It is naught) save mercy from thy Lord. Lo! His kindness unto thee was ever great. 87 Say: "If the mankind and the jinns were together to produce the like of this Quran, they could not produce the like thereof, even if they helped 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 And say: "We will not believe you until you make a spring of water gush forth from the earth for us; 90 or you (show) us that you have your own garden of palm trees and vines with flowing streams therein, 91 or cause the sky to fall on us in pieces as you claimed, or bring Allah and the angels before us, face to face; 92 Or you should have a house of gold, or you should ascend into heaven, and we will not believe in your ascending until you bring down to us a book which we may read. Say: Glory be to my Lord; am I aught but a mortal apostle? 93