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 Except as a mercy from thy Lord verily His grace unto thee is ever 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 And certainly We have explained for men in this Quran every kind of similitude, but most men do not consent to aught but denying. 89 And they said, “We will not accept faith in you, until you cause a spring to gush forth from the earth for us.” 90 Or [until] you have a garden of palm tress and grapes and make rivers gush forth within them in force [and abundance] 91 or, until you cause the sky to fall upon us in pieces, as you have claimed, or, as a surety bring Allah with the angels in front; 92 or you have a house made of gold; or you ascend to heaven; and we will not believe in your ascension until you send down to us a Book that we can read." Tell them, "Holy is my Lord. I am but a human being sent as a messenger." 93