The date of the Prophet of Islam’s (Peace Be Upon Him and His Family) mission’s onset has been a subject of variation in terms of specification and determination. It is like the day of his birth and the day of his demise (Peace Be Upon Him and His Family) where no definitive date is agreed upon by historians and biographers.
Shi’a scholars unanimously agree that the Prophet (Peace Be Upon Him and His Family) began his prophetic mission on the 27th of Rajab. They believe that the revelation began on that very day. Conversely, among Sunni scholars, it is popularly held that the Prophet of Islam attained this esteemed status in the blessed month of Ramadan. It was in this sacred month that Muhammad (Peace Be Upon Him and His Family) was mandated by Allah to guide people and was conferred with prophethood.
Since the Shi’a revere the Prophet’s family (Peace Be Upon Him and His Family) and firmly believe in the veracity of their sayings and teachings, following the Prophet’s declaration about them in the “Hadith of the Two Weighty Things” stating, “The two will never separate,” they chose to follow the widely transmitted and reliably narrated account from the immaculate family of the Prophet in this regard.
It has been narrated from the offspring of the Prophet and his pure lineage that the luminary of this house, its master (i.e., the Prophet), started his mission on the 27th of Rajab, and their word stands as proof. Therefore, there can be no doubt or hesitation about the authenticity and verification of this statement.
The strongest evidence that can be presented for the opposing view is the Qur’an itself, which explicitly states that the verses of the Qur’an were revealed in the month of Ramadan. Given that the day of the Prophet’s mission (Peace Be Upon Him and His Family) was the very day the revelation began, and the Qur’an was revealed upon him, it is necessary to state that the sacred mission’s day was indeed in the same month the Holy Qur’an was revealed: the blessed month of Ramadan.
Below are the verses indicating that the Holy Qur’an was revealed in the month of Ramadan:
1- “The month of Ramadan [is that] in which was revealed the Qur’an.”
2- “Ha, Meem. By the clear Book, Indeed, We sent it down during a blessed night. Indeed, We were to warn [mankind].”.This night refers to the Night of Power, about which He (Exalted) said: “Indeed, We sent it [Qur’an] down during the Night of Power. The Night of Power is better than a thousand months.”
Shi’a Scholars’ Response:
Shi’a scholars and exegetes have various responses to this argument, a few of which are mentioned here:
The First Response:
The aforementioned verses only indicate that the Qur’an was revealed in the month of Ramadan, specifically on the “Night of Power.” However, they do not specify the exact place of the revelation or where it was revealed. Therefore, these verses cannot conclusively indicate that it was revealed to the heart of the Prophet on that very night.
It is possible that the Qur’an had multiple descents. One being its gradual revelation to the Prophet and the other being its collective revelation from the “Preserved Tablet” to the “Frequented House”. Hence, what stops some verses of the Qur’an (from the chapter ‘Al-Alaq’) from being revealed to the Prophet (Peace Be Upon Him and His Family) on the 27th of Rajab? Later, the entire Qur’an was revealed in the month of Ramadan from a specific location named in the Qur’an as the “Preserved Tablet” to another place, which some traditions refer to as the “Frequented House.”
Supporting this view is the verse from Surah Al-Dukhan: “Indeed, We sent it down during a blessed night.” This verse, referring to the entire book, clearly states that the entire illustrious book was revealed on a blessed night (in Ramadan). This descent must be different from the descent on the day of the Prophetic mission since only a few verses were revealed on the day of the mission.
In conclusion, the verses explicitly stating the Qur’an’s descent in Ramadan on the Night of Power cannot indicate that the day of the Prophetic mission, during which only a few verses were revealed, was also in that same month. The mentioned verses indicate that the entirety of the Qur’an, not just a part of it, was revealed in that month. However, on the day of the Prophetic mission, only a few verses were revealed, as we know.
In this context, the collective descent of the Qur’an might refer to the entirety of the illustrious book being revealed in that month from the “Preserved Tablet” to the “Frequented House.” Both Shi’a and Sunni scholars have narrated traditions with this content, especially the Azhari scholar Muhammad Abdul Azim Al-Zarqani, who mentioned several narrations on this matter in his book.
The Second Response:
This is among the more profound answers to the aforementioned point.
Renowned scholar Al-Tabatabai has made a significant effort to elucidate and explain this in his esteemed book. Here’s a summary: Al-Tabatabai states that when Allah Almighty says, “Indeed, We sent it [Qur’an] down in the month of Ramadan,” it signifies the actual descent of the Qur’an into the Prophet’s heart (Peace Be Upon Him and His Family). This is because the Qur’an, apart from its gradual revelation, embodies a reality that Allah made known to His esteemed Prophet on a particular night of the blessed month of Ramadan.
Given that the honorable Prophet (Peace Be Upon Him and His Family) was already familiar with the entire Qur’an, a verse was revealed instructing him not to hasten with its recitation until the directive for its gradual revelation was given. The Exalted says, “Do not hasten with the Qur’an before its revelation is completed to you.”
The crux of this response is that the Qur’an possesses a collective, real, and intellectual existence, which descended upon the noble Prophet (Peace Be Upon Him and His Family) all at once during Ramadan. In contrast, another existence is its gradual revelation, which began on the day of the Prophetic mission and continued in this manner until the end of His noble life.
The Third Response
Differentiating Between the Descent of the Qur’an and the Prophetic Mission
Revelation, as briefly discussed in the subject of the types of revelation, has stages. Its initial stage is represented by the truthful visions experienced by the Prophet (Peace Be Upon Him and His Family).
Another stage was when he heard the divine, unseen call without angelic mediation. The final stage is when the Prophet hears Allah’s words through an angel, whom he can see and recognize, enabling him to understand the realities of other worlds.
Considering that the human soul cannot initially endure all levels of revelation at once but must adapt gradually, we must say that on the day of the Prophetic mission (the 27th of Rajab), the Prophet (Peace Be Upon Him and His Family) heard only the celestial call, informing him of his Prophethood. No verse was revealed on that day. This state continued for a while before the gradual revelation of the Qur’an commenced, starting in the month of Ramadan.
In summary, this response posits that the initiation of the Prophet’s (Peace Be Upon Him and His Family) mission in Rajab does not necessarily mean that the Qur’an was revealed in that month.
Based on this foundation, what prevents the idea that Prophet Muhammad (Peace Be Upon Him and His Family) was commissioned in the month of Rajab, and the Holy Qur’an was revealed in the month of Ramadan of the same year?
Although this answer may not agree with many historical texts (since many historians have stated that the first five verses of Surah Al-‘Alaq were revealed on the very day of the commissioning), there are still narrations that describe the story of the commissioning as Prophet Muhammad (Peace Be Upon Him) hearing a divine call. These accounts do not mention any Qur’anic revelations or verses. Instead, they explain the event as follows: on that day, the Prophet Muhammad (Peace Be Upon Him) heard an angel telling him: “O Muhammad, you are indeed the Messenger of Allah.” Some reports even mention that he only heard this proclamation without seeing any angel.
The Prophets and the Prophecy of Prophet Muhammad
To complete this chapter of prophetic history, it’s essential to point out to the esteemed reader that the blessed Muhammadan message was foretold by all preceding prophets.
The Holy Qur’an alludes to this, where Allah says: “And [recall, O People of the Scripture], when Allah took the covenant of the prophets, [saying], ‘Whatever I give you of the Scripture and wisdom and then there comes to you a messenger confirming what is with you, you [must] believe in him and support him.’ [Allah] said, ‘Have you acknowledged and taken upon that My commitment?’ They said, ‘We have acknowledged it.’ He said, ‘Then bear witness, and I am with you among the witnesses.'” 
This verse, while revealing a general principle—that every previous prophet should validate and support the subsequent prophet— its most complete manifestation is Prophet Muhammad. This indicates that Allah took a firm covenant from all prophets or from the major ones with legislative roles to believe in and support Prophet Muhammad and to call their followers to do the same. Al-Fakhr al-Razi narrated from Imam Ali (Peace Be Upon Him): “Allah didn’t send Adam or any prophet after him without taking a covenant from them that if Muhammad were sent in their lifetime, they would believe in and support him.” 
Among the things that support this is that the Qur’an has called upon the People of the Book to clarify what they have read and found in their books about the Messenger of Islam to the people without concealing it. Here are some verses that explicitly mention this matter:
1- Allah Almighty says: “And when Allah took a covenant from those who were given the Scripture: ‘You must clarify it for the people and not hide it.’ Yet they threw it behind their backs and bought with it a small gain. How terrible is what they bought!” 
2- Allah says: “Indeed, those who conceal what Allah has sent down of the Book and exchange it for a small price – those consume not into their bellies except the Fire. And Allah will not speak to them on the Day of Resurrection, nor will He purify them. And they will have a painful punishment.” 
3- Allah says: “Those to whom We gave the Scripture know him [Muhammad] as they know their own sons. But indeed, a party of them conceal the truth while they know [it].” 
4- The Exalted says: “Those who follow the Messenger, the unlettered prophet, whom they find written in what they have of the Torah and the Gospel, who enjoins upon them what is right and forbids them what is wrong and makes lawful for them the good things and prohibits for them the evil and relieves them of their burden and the shackles which were upon them. So those who have believed in him honored him, supported him, and followed the light which was sent down with him – it is those who will be the successful.” 
The Qur’an clearly states that Jesus (Peace Be Upon Him) informed about the Messenger of Islam and his message, saying: “And [mention] when Jesus, the son of Mary, said, ‘O children of Israel, indeed I am the messenger of Allah to you confirming what came before me of the Torah and bringing good tidings of a messenger to come after me, whose name is Ahmad.’ But when he came to them with clear evidences, they said, ‘This is obvious magic.'” 
The Qur’an also talks about the People of the Book who denied the message of Prophet Muhammad (Peace Be Upon Him) when he was sent. They used to inform about him beforehand and sought his support against their enemies. The Exalted said: “And when there comes to them a Book from Allah, confirming what is with them – although before they used to pray for victory against those who disbelieved – but [then] when there came to them that which they recognized, they disbelieved in it; so the curse of Allah will be upon the disbelievers.” 
Furthermore, the Qur’an informs us that when Abraham (Peace Be Upon Him) settled his wife and son Ishmael in the land of Mecca, he prayed: “Our Lord, and send among them a messenger from themselves who will recite to them Your verses and teach them the Book and wisdom and purify them. Indeed, You are the Exalted in Might, the Wise.” 
These descriptions have indeed matched the Messenger of Allah, peace and blessings be upon him and his family, as the Noble Qur’an describes him, saying: “Allah has truly favored the believers when He raised up in their midst a messenger from among themselves, reciting to them His verses, purifying them, and teaching them the Book and wisdom, while earlier they were in clear error.” 
Muhammad, the Seal of the Prophets
To complement this article, it is also essential to highlight the most prominent aspect of the Prophet Muhammad’s, peace and blessings be upon him and his family, message, and his prophethood: the matter of being the final prophet. The Noble Qur’an explicitly states in many verses that the Messenger of Allah, Muhammad, peace and blessings be upon him and his family, is the seal of the prophets, and his law is the final law. There is no prophet after him, and no message after his.
Below are some of the prominent verses in this regard:
1- Allah Almighty says: “Muhammad is not the father of [any] one of your men, but [he is] the Messenger of Allah and the last of the prophets. And Allah is ever Knowing of everything.” 
2- The Exalted says: “Blessed is He who sent down the Criterion upon His Servant that he may be a warner to the worlds.” 
3- The Exalted says: “And this Qur’an was revealed to me that I may warn you thereby and whomever it reaches.” 
4- Allah Almighty says: “We have only sent you as a universal [messenger] to give good news and to warn, but most people do not know.” 
The last three verses indicate that the message of the Prophet Muhammad, peace and blessings be upon him and his family, is universal, global, and eternal. Otherwise, in any other circumstance or form, he would not be a prophet for all people and for all worlds. He wouldn’t be a warner for his people and all those who hear his call.
The Prophet himself, peace and blessings be upon him and his family, clarified in many narrations on this topic, being the truthful who affirms. Abu Hurairah reported that the Messenger of Allah, peace and blessings be upon him and his family, said: “I was sent to all people, and with me, the line of prophets is sealed.”
1- See “Bihar al-Anwar”: Vol. 18, page 189.
2- Al-Baqarah: 185.
3- Ad-Dukhan: 1 – 3.
4- Al-Qadr: 1 and 3.
5- To understand the meaning of “Al-Lawh Al-Mahfuz”, refer to the Tafsir (Quranic exegesis) books.
6- “Manahil al-Irfan fi Ulum al-Quran”: Vol. 1, page 37.
7- “Al-Mizan”: Vol. 2, pages 14 – 16.
8- Ta-Ha: 114.
10- Aal-E-Imran: 81.
11- “Mafatih al-Ghaib”: Vol. 2, page 507.
12- Aal-E-Imran: 187.
13- Al-Baqarah: 174.
14- Al-Baqarah: 146.
15- Al-A’raf: 157.
16- As-Saff: 6.
17- Al-Baqarah: 89.
18- Al-Baqarah: 129.
19- Aal-E-Imran: 164.
20- Al-Ahzab: 40.
21- Al-Furqan: 1.
22- Al-An’am: 19.
23- Saba: 28.
24- “Al-Tabaqat Al-Kubra”: Vol. 1, page 128.