The Qur'an Is Protected from Change:  

The Qur'an Is Protected from Change:
• The Qur'an is "confirming the scripture that was before it and stands as a
guardian over it." Thus, by means of the Qur'an, Allah abrogated all the
previous revealed books. Allah has also guaranteed its protection from any
play or mischievous distortion: "Indeed, We sent down the message and We
will guard it" (15:9), for the Qur'an is a proof against mankind till the Day
of Judgment.
Previous Scriptures Changed:
• The previous scriptures were meant for a limited period. Their use ended
with the revelation of the Qur'an, which abrogated them and exposed their
distortions and changes. That is why they were not protected from
corruption. They underwent distortion, addition, and omission: "Some of
the Jews pervert words from their meanings" (4:46); "So woe to those who
write the Book with their hands, and then say: 'This is from Allah,' 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" (2:79); "Say, who sent down
the Book that Moses brought as a light and a guidance to people? You put it
into sheets of paper showing some of them and concealing much" (6:91);
"And there is a group among them who twist their tongues with the Book,
that you may think it is a part of the Book but it is not part of the Book.
And they say 'It is from Allah,' yet it is not from Allah, and they tell a lie
against Allah and they know it. It is not for any human being to whom
Allah has given the Book, the Wisdom and the Prophet hood to say to men
'Worship me instead of Allah"' (3:79); "People of the Book! Our
Messenger has come to you, making clear to you many things you have
been concealing of the Book and forgiving you of much. A light has come
to you from Allah and a glorious Book, with which He will guide whoever
follows His pleasure in the way of peace, and brings them forth from
darkness into the light by His will" (5:15-16).