Tahrif is an Arabic word used to refer to the Bible’s alleged corruption. Various passages in the Quran assert the corruption of the Jewish and/or Christian Scriptures (see Quran 2:42,59, 75-9; 3:71, 78; 4:46; 5:13, 41; 6:91; 7:162).
Tahrif has traditionally denoted one of two things when applied to the Christian and Jewish Scriptures. The first is that the meaning of the text has been misrepresented in translation or interpretation (tahrif al-maʿānī,). The second is that the text has been intentionally changed (tahrif al-nass).
Usually questions of tahrif focus on the Bible; however, the Quran is guilty of tahrif al-nass because Muslims believe the Quran completely replaces the previous Scriptures of the Jews and Christians. The Quran is also guilty of tahrif al-maʿānī, and this is most clearly demonstrated in its regard of Jesus’ crucifixion.
The Quranic Injil is a corruption of the Scriptures
The Quran wrongly teaches that Jesus was given a book (Injil) from heaven (Qur’an 5:46-47; 57:27). Muslims then judge the Christian gospels, written years after Jesus ascended into heaven, by the Qur’an and Qur’anic Injil.
The Qur’anic corruption is that it invents a text that does not exist and never existed. Jesus was never given a book from heaven and He never gave such a book to His followers.