Quran 2:75-79

75 Are you then so eager that they should believe you, seeing there is a party of them that heard God's word, and then tampered with it, and that after they had comprehended it, wittingly? 76 And when they meet those who believe, they say 'We believe'; and when they go privily one to another, they say, 'Do you speak to them of what God has revealed to you, that they may thereby dispute with you before your Lord? Have you no understanding?' 77 Know they not that God knows what they keep secret and what they publish? 78 And some there are of them that are common folk not knowing the Book, but only fancies and mere conjectures. 79 So woe to those who write the Book with their hands, then say, 'This is from God,' that they may sell it for a little price; so woe to them for what their hands have written, and woe to them for their earnings.