The Quran describes itself as "the discernment" (al-furqān), "the mother book" (umm al-kitāb), "the guide" (huda), "the wisdom" (hikmah), "the remembrance" (dhikr) and "the revelation" (tanzīl; something sent down, signifying the descent of an object from a higher place to lower place).Another term is al-kitāb (The Book), though it is also used in the Arabic language for other scriptures, such as the Torah and the Gospels.The term mus'haf ('written work') is often used to refer to particular Quranic manuscripts but is also used in the Quran to identify earlier revealed books.
However, the Quran did not exist in book form at the time of Muhammad's death in 632.
Sahih al-Bukhari narrates Muhammad describing the revelations as, "Sometimes it is (revealed) like the ringing of a bell" and Aisha reported, "I saw the Prophet being inspired Divinely on a very cold day and noticed the sweat dropping from his forehead (as the Inspiration was over)." The Islamic studies scholar Welch states in the Encyclopaedia of Islam that he believes the graphic descriptions of Muhammad's condition at these moments may be regarded as genuine, because he was severely disturbed after these revelations.
The latter two terms also denote units of revelation.
In the large majority of contexts, usually with a definite article (al-), the word is referred to as the "revelation" (waḥy), that which has been "sent down" (tanzīl) at intervals.
There are, however, variant readings, with mostly minor differences in meaning.
The Quran assumes familiarity with major narratives recounted in the Biblical scriptures.
The final verse of the Qur'an was revealed on the 18th of the Islamic month of Dhu al-Hijjah in the year 10 A.
H., a date that roughly corresponds to February or March 632.
In order to extrapolate the meaning of a particular Quranic verse, most Muslims rely on exegesis, or tafsir.
The term also has closely related synonyms that are employed throughout the Quran.
For example, according to Fakhr al-Din al-Razi, if Muhammad had mastered writing and reading he possibly would have been suspected of having studied the books of the ancestors.