Mas’alah 1: Allah has revealed many big and small books to Prophets through the angel Jibra’eel so that they may guide, teach and explain religious problems to their respective Ummats (communities).
Of all these -four books are very famous. Tauraat was given to Prophet Moosaa (Moses), Zaboor (Psalms) to Prophet Daawood (David), Injeel (Bible) to Prophet Eisaa (Jesus) and the Holy Qur’aan to our Holy Prophet Muhammad Sallallaahu alayhi wasallam, which is the last- revealed book.
No other book-shall now be revealed and the instructions of the Holy Qur’aan shall rule till the Day of Judgement.
Some aberrated persons have intentionally interpolated in other books but the preservation of the Holy Qur’aan has been promised by Allah. No one can change it in any way.
 
Companions of the Prophet Sallallaahu alayhi wasallam