The Holy Quran has summarized the various kinds of revelation in the following words:
“And it is not possible for a human being that Allah should speak to him, except by way of revelation, or from behind a curtain, or that He should send a messenger and he reveals by His leave what He wills.” (42:51)
Now, out of these thee modes, the revelation of the Holy Quran was carried out through the third one, namely, through an angel who is identified in the verse by the word, ‘messenger’. It is clearly settled by some other verses:
“Say, whoever be an enemy to Jibril (Gabriel, the angel)- it is he who has brought it (the Quran) down upon your heart by the permission of Allah.” (2:97)
“And truly, it (the Quran) is the revelation of the Lord of the worlds, brought down by the Faithful Spirit upon your heart, that you may be one of the warners, in a clear Arabic tongue.” (26:129,195)
These verses are quite explicit on the point that, the Holy Quran has been revealed through an angel, named in the first verse as Jibril, and in the second one as the Faithful Spirit; but the verse (42:51) quoted above describes that, there are two more ways of revelation. These two modes have also been used in the case of the Holy Prophet (SAWS). It means that the revelation sent down to the Holy Prophet (SAWS) was not confined to the Holy Quran, but there were other revelations, too. These revelations are termed as ‘unrecited revelation’.