Al-An'am - 6:7

وَلَوْ نَزَّلْنَا عَلَيْكَ كِتَابًا فِي قِرْطَاسٍ فَلَمَسُوهُ بِأَيْدِيهِمْ لَقَالَ الَّذِينَ كَفَرُواْ إِنْ هَـذَا إِلاَّ سِحْرٌ مُّبِينٌ
[6:7]
And if We had sent to you a writing on a paper, then they had touched it with their hands, certainly those who disbelieve would have said: This is nothing but clear enchantment.
If We had sent unto thee a written (message) on parchment, so that they could touch it with their hands, the Unbelievers would have been sure to say: "This is nothing but obvious magic!"
Had we sent down unto thee (Muhammad) (actual) writing upon parchment, so that they could feel it with their hands, those who disbelieve would have said: This is naught else than mere magic.