Wahi is Allah’s system of communication with His creatures. Wahi is Allah’s message to His creatures; Allah sends wahi down to honey bees (al-nahl-68); Allah sends down wahi to skies (Hamim Sajda-12); Allah sends down wahi to the earth (al-zalzalah-5). Similarly Allah initiates wahi to humans; Allah sent wahi to Hazrat Esa’s (as) companions (al-maida-111); Allah sent wahi to Hazrat Musa’s (as) mother (al-qasas-7; Taha-38). Similarly, Allah sent down wahi to His Messengers (Yusuf-109; al-nahl-43; al-anbia-7,25). But it may be noted that Hazrat Esa’s companions and Hazrat Musa’s mother were not Prophets but even then wahi was sent upon them; it means wahi has two types in respect of its recipients; first, that is sent down to non-Prophets, and second, that is sent down to Prophets (as). It may also be noted that wahi is sent down to all Messengers (as) but it is not sent down to all non-Prophets (al-anam-93); in other words, wahi is sent down to only selected humans.
Wahi is initiated by Allah through an Angel; in fact sending down an Angel carrying Allah’s message is called wahi (al-shura-52). This verse (al-shura-52) states “We made “wahi” to you [Muhammad (saw)] an Angel (Hazrat Gabriel) with Our command”. It means sending down an Angel by Allah is called wahi; but sent down Angel must have Allah’s message to reveal onto the subject person/creature. Sending down an Angel for a purpose other than revealing Allah’s message is not called wahi; Angels are sent down to people for many various purposes other than revealing Allah’s message.
There is another type of 'wahi' which is directly revealed to a Rasool without mediation of Hazrat Gabrael. Sura al-shura-51 describes three methods of Allah's communication with mankind;i. through 'wahi';ii. from behind a veil; iii. and through an angel. We have seen above sending down an angel with a message is called 'wahi'; this type of 'wahi' has been described in the third method in this verse-51; this method is associated with both a 'Rasool' and a Nabi as well as with non-prophet. The first method is associated with 'Rasool' only; in this method of wahi, revelation is made without Hazrat Gabrael. Sura Jin-26-27 states "He is Knower of the unseen, and He does not disclose His [knowledge of the] unseen to anyone. Except whom He has approved of Messengers (Rasool).......,". It is clear from these verses that only a 'Rasool' is given such knowledge of unseen, which is earlier confined to Allah only, and such knowledge is NOT given to anybody including an angel. it means such knowledge/wahi is initiated without an angel.
The two types of wahi- pertaining to Prophets and non-Prophets- are different not only in respect of recipients but also in respect of form and medium through which these are initiated.
Wahi to a Rasool is initiated through Hazrat Gabriel (as) or directly by Allah;when in the form of Book, it is revealed through Gabrael (as) in the form of Allah's words [it is the basic identity of a Rasool that he is given Book/'saheefa'(ale-Imran-184)]; when directly from Allah without any Angel, it is revealed in the form of Allah's Idea translated into words by the Rasool himself.
Wahi to a 'Nabi' is initiated through Hazrat Gabrael and in the form of Allah's Idea translated into words by Hazrat Gabrael or by the 'Nabi' himself; A Nabi may also be given a portion of a Book to be revealed completely to a Rasool, but this partial Book is revealed not in the form of Allah's words; rather it is revealed in the form of Allah's Idea translated into words by Gabrael or by Nabi himself (al-Imran-81). ( for detail plz see my article " Universality of Resalat, Ummah and Qadyaniat"). Wahi to non-Prophets is sent down by Angels other than Hazrat Gabriel (as).
All prophets received wahi through Gabrael (as) or directly from Allah without mediation of any Angel. Sura al-nisa-163 states that “Indeed, We have revealed to you [ Muhammad(saw)] as We revealed to Noah and the prophets after him”. It means all forms and methods of revelation applied to all previous Prophets combined were also applied to Muhammad (saw). These forms of revelation have two types; first in the form of Allah’s words (e.g. Quran; and other revealed Books); and second, in the form of Allah’s idea translated into words either by Hazrat Gabriel (e.g. “hadith –e-Qudsi”) or translated by the Messenger or Nabi (as) himself (e.g. common hadith). These both forms were initiated through Hazrat Gabriel (as) OR directly by Allah. The Sura al-shuaara-193 and al-nahl-102 state about Quran that it has been revealed through Hazrat Gabriel (Ruhul Amin and Ruhul Quds). Similarly, the Sura al-anaam-50 describes about Muhammad (saw) “say……I only follow what is revealed to me." It means Quran and Sunnah both are based on wahi; and wahi was revealed through Hazrat Gabrael ( there is no single rawayat which say that wahi was revealed through an angel other than Hazrat Gabrael), or directly by Allah, as al-Shura-51 mentions/implies. In other words, all other Prophets received revelation through Hazrat Gabriel (as)or directly from Allah because all other Messengers and Nabis received revelation in the way Muhammad (saw) received (Nisa-163).
Some other verses also endorse this fact that all prophets received revelation through Gabriel (as). It may be noted that words “alruh/ruhul Quds/ruhul Amin” are always used in Quran for Hazrat Gabriel (as) (the instances are Ghafir-15; Sura Nahl-2,102; Sura Qadr-4;Sura Niba-38; Sura Maarij-4;Sura Shuara-193 and in Sura bni Israel-85). Whereas the word “ruh” may be used for Angels other than Hazrat Gabriel (as)[e.g. Maryam-17].
Sura Ghafir-15 states “He sends His Spirit (alruh) by His command to whichever of His servants He wants to warn them of the Day of Judgment”. . Sura Nahl-2 states “He sends down the angels with the Spirit (alruh) by His Command to whom of His slaves He pleases…...”(sending of “alruh” is for revelation, and other angels for other purposes). Breifly speaking, we can conclude that all Prophets received revelation through Hazrat Gabriel (as) or directly from Allah.
It becomes clear from foregoing that whatever is the form of revelation a Prophet received, he received revelation only through Hazrat Gabriel (as) or directly from Allah.
Non-Prophets may receive revelation through Angels other than Gabriel. Sura Maryam-17 states about Hazrat Maryam (as) “And she took, in seclusion from them, a screen. Then We sent to her Our Angel (ruh), and he represented himself to her as a well-proportioned man”. This angel came down to Maryam for revealing to her Allah’s message which has been described in the same Sura in verse 19 which states “he(angel) said, "I am only the messenger of your Lord to give you [news of] a pure boy”. In this verse, word “ruh” has been used which is used for angel other than Gabriel (as).
Another difference between Prophetic wahi and non-Prophetic wahi is that Prophetic wahi is to be compulsorily accepted/complied with by the ummah of the Messenger. But non-Prophetic wahi is for personal guidance of the person receiving wahi; Hazrat Isa’s companions and Hazrat Musa’s mother received wahi for their personal guidance; it means non-Prophetic wahi is to be complied with by the person receiving that wahi; other people are not bound to believe in or comply with such wahi. A person receiving non-Prophetic wahi, after coming of Muhammad (saw), has to test rightness or wrongness of that wahi on the basis of Quran and Sunnah. The Quran says “And indeed do the devils make revelation to their allies [among men] to dispute with you. And if you were to obey them, indeed, you would be surely polytheists” (anam-121). Similarly Quran says “And thus We have made for every prophet an enemy - devils from mankind and jinn, making revelation to one another of decorative speech in delusion. But if your Lord had willed, they would not have done it, so leave them and that which they invent” (anam-112). From these verses it is clear that devils from Jinn and mankind can also make revelation to humans; therefore, after coming of Muhammad (saw), recipient of non-Prophetic wahi (who is not as much protected by Allah as the Prophet Muhammad (saw) is) has to accept or reject such wahi on the basis of Quran and Sunnah; any such wahi which is not in consonance with Quran and Sunnah is not a wahi from Allah and has to be rejected outrightly.
In contrast to wahi, Intuition (ilham) has nothing to do with Angels or Allah’s special message. In fact, intuition consists of intellectual faculties naturally and inherently built in mankind. Sura al-shams-8 reveals about mankind “Then He (Allah) inspired (ilham) into him (mankind) what is wrong for him and what is right for him”. This human ability to know what is wrong for him and what is right for him is called intuition and it is inherently present in each and every man; every person can use this ability without any special message received from Allah or without any special angel sent down to him by Allah. In other words, intuition is a ability common to all mankind; it is not confined to certain people. Intuition has nothing to do with past, present or future news; nor is it related to special knowledge of things. It is related to knowledge of things only to the extent of human ability to differentiate between the right deed and the wrong deed in the situation presented to him.