(Asshuara’) 26 : 194
عَلَىٰ قَلْبِكَ لِتَكُونَ مِنَ الْمُنْذِرِينَ
Upon your heart so that you may be among the warners.
Instead of saying: “upon your tongue”, it is told: “upon your heart”. From that it is clear that Lord doesn’t send down the body of the Book, instead, he sent down Adhikr which is the Soul of the Book. See explanation 15: 6, 9, and 16: 43-44.