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 so willed, We could indeed take away whatever We have revealed unto thee, and in that [state of need] thou wouldst find none to plead in thy behalf before Us. 86 Except [We have left it with you] as a mercy from your Lord. Indeed, His favor upon you has ever been 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 explained things for people in this Qur'an in diverse ways to make them understand the Message, yet most people obstinately persist in unbelief. 89 and so they say: "[O Muhammad,] we shall not believe thee till thou cause a spring to gush forth for us from the earth, 90 Or you should have a garden of palms and grapes in the midst of which you should cause rivers to flow forth, gushing out. 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