They ask you about "the spirit". Say: "The spirit descends by the command of my Lord, but you have been given only a little knowledge." 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 [We have left it with you] as a mercy from your Lord. Indeed, His favor upon you has ever been great. 87 Say: "Surely, if mankind and jinn were to get together to produce the like of this Qur'an, they will never be able to produce the like of it, howsoever they might help one another." 88 And We have explained to man, in this Qur'an, every kind of similitude: yet the greater part of men refuse (to receive it) except with ingratitude! 89 And they say: "We shall not believe in you (O Muhammad SAW), until you cause a spring to gush forth from the earth for us; 90 or till thou possessest a garden of plants and vines, and thou makest rivers to gush forth abundantly all amongst it, 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 till thou possessest a house of gold ornament, or till thou goest up into heaven; and we will not believe thy going up till thou bringest down on us a book that we may read. Say: 'Glory be to my Lord. Am I aught but a mortal, a Messenger?' 93