There are six main texts consulted by Muslims:
The Qur'an (Recitation) are the literal words of God in their original Arabic language. Muslims believe that it was dictated to Muhammad by the archangel Jibril over an interval of 23 years. The text was originally in oral and written form; it was later assembled together into a single book, the Qur'an. Its name is often spelled "Koran" in English. This is not recommended, as some Muslims find it offensive. It is the only book that is considered free of tahrif (error).
There are four additional revealed books:
The Suhuf-i-Ibrahim (Scrolls of Abraham/Ibrahim) which most Muslims believe have been lost.
The Tawrat (a.k.a Tawrah or Taurat) This is the Pentateuch, the first five books from the Hebrew Scriptures (Old Testament). Many Muslims believe that the text has been altered by ancient Hebrew
The Zabur which many Muslims believe are the Psalms from the Hebrew Scriptures. According to the Qur'an, the Zabur was revealed to David when he was king of Israel.
The Injil (a.k.a. Injeel). These are the Gospels, referred to as the words of Jesus, Some Muslims believe that this consists of the entire Christian Scriptures (New Testament); others believe it refers to only the four canonical Gospels. The Injil are also believed to have been distorted and corrupted over time. Other Muslims believe that the Injil is not a book, but a lost group of teachings written by the apostles or authors connected to the apostles.
The Hadith, which are collections of the sayings of Muhammad (pbuh). They are regarded as the Sunnah (lived example) of Muhammad. The Quran gives legitimacy to the Hadith. It states: "Nor does he say aught of his own desire. It is no less than inspiration sent down to him" (53:3-4). However, the writings are not regarded as having the same status as the Holy Qur'an; the latter is considered to be God's word. The great Islamic scholar Yahya bin Sharaf Ul-Deen An-Nawawi compiled a collection of 43 sayings of Prophet Muhammad (PBUH). It is is now known as "Al-Nawawi's Forty Hadiths"