What is Revelation?
Revelation is the words of Allah told to the prophets chosen by Him among human beings to convey those words to human beings. (Cerrahoğlu Prof.Dr. İsmail, Tefsir Usûlü p.39, Ankara 1979.)
Revelation is the knowledge and information that prophets find in their spirits (hearts) directly or indirectly.
It is not appropriate to try to explain revelation through material things. It is something peculiar to prophets. A being that is not an angel does not know what it is like to be an angel. A person who is not a prophet cannot experience and know prophethood truly. However, the existence of revelation is definite.
"The Owner and Master of this universe does everything with knowledge, disposes every affair with wisdom, directs everything all-seeingly, treats everything all-knowingly, and arranges in everything with His will and wisdom such causes, purposes and uses that are apparent to us. Since the One who creates knows, surely the One who knows will speak, since He will speak, surely He will speak to those who have consciousness, thought, and speech. Since He will speak to those who have thought, surely He will speak to humankind, whose make-up and awareness are more comprehensive of all conscious beings. Since He will speak to humankind, surely He will speak to the most perfect of mankind and those most worthy of address …"(Badiuzzaman Said Nursi, Mektubat (Letters), p. 89)
Prophets receive the decrees and truths from Allah through revelation. All of the prophets received revelation from Allah.
The following verse shows that revelation is something common and valid for all prophets:
"We have sent thee inspiration as We sent it to Noah and the Messengers after him; We sent inspiration to Abraham, Ismail, Isaac, Jacob, and the Tribes to Jesus, Job, Jonah, Aaron, and Solomon, and to David, We gave the Psalms"(an-Nisa, 4/163)
There are many kinds and degrees of revelation:
The most common kind of revelation is the conveyance of the divine decrees to prophets through Gabriel, the angel of revelation. The Quran was sent down like that. Gabriel conveyed the revelation in different forms. He sometimes brought revelation as he was, that is, as an angel; he sometimes brought revelation disguised as a man. Sometimes, he came without being seen, with the sound of a bell or buzz and placed the revelation into the heart of prophets.
Sometimes, Allah makes His prophets hear the commands and decrees directly. For instance, Moses received revelation directly from Allah in the Mount Sinai and Hazrat Prophet received revelation directly from Allah during the Ascension (Miraj).