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 Had We willed, We could take away what We have revealed to you, then you would find none to help you in recovering it from Us. 86 Except as a mercy from thy Lord verily His grace unto thee is ever great. 87 Say, "If all men and jinn gathered together to produce the like of this Quran, they could not produce one like it, however much they helped one another." 88 And verily We have displayed for mankind in this Qur'an all kind of similitudes, but most of mankind refuse aught save disbelief. 89 And say: "We will not believe you until you make a spring of water gush forth 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 till thou makest heaven to fall, as thou assertest, on us in fragments, or thou bringest God and the angels as a surety, 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