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 willed We could withdraw that which We have revealed unto thee, then wouldst thou find no guardian for thee against Us in respect thereof. 86 except by the mercy of your Lord. He has certainly bestowed great favors on you. 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 certainly We have explained for men in this Quran every kind of similitude, but most men do not consent to aught but denying. 89 They say, 'We will not believe thee till thou makest a spring to gush forth from the earth for us, 90 or, until you own a garden of palms and vines and cause rivers to gush forth with abundant water in them; 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 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