They ask thee concerning the Spirit (of inspiration). Say: "The Spirit (cometh) by command of my Lord: of knowledge it is only a little that is communicated to you, (O men!)" 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 Unless your Lord have mercy. His blessings on you are great indeed. 87 Say: 'If men and jinn banded together to produce the like of this Koran, they would never produce its like, not though they backed 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 thou have a garden of date-palms and grapes, and cause rivers to gush forth therein abundantly; 91 Or, let chunks of sky fall over us, as you assert (you will); or, bring God and the angels as a surety; 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