According to Allaah’s statements in His Book, there were two distinct revelations of the Qur’aan which took place. It is important that these two revelations be understood in order to clear up the apparent contradictions in the various terms used in the Qur’aan and Sunnah to describe the Qur’aan’s revelation. On one hand, the Qur’aan is referred to as having been revealed in its totality in Ramadaan or on Laylatul-Qadr, the Night of Decree; while on the other hand, it is referred to as having been continuously revealed in segments up until just before the death of the Prophet (sallallaahu `alayhi wa sallam).
The First Revelation
Allaah caused the Qur’aan to descend from the Protected Tablet (al-Lawh al-Mahfooth) on which it was written to the lowest heaven. In this revelation all of the Qur’aan was sent down at one time to a station in the lowest heaven referred to as “Bayt al-‘Izzah” (The House of Honor or Power). The blessed night on which this descent took place is called “Laylatul-Qadr” (The Night of Decree), one of the odd-numbered nights in the last ten days of the month of Ramadaan. Allaah referred to this initial revelation as follows:
“Haa Meem. By the Clear Book, verily, I revealed it in a blessed night.” (Soorah ad-Dukhaan 44:1-3.)
“Verily, I revealed it on the Night of Decree.” (Soorah al-Qadr 97:1)
“The month of Ramadaan in which I revealed the Qur’aan as guidance to mankind …” (Soorah al-Baqarah 2:185.)
These verses have to refer to the initial revelation because it is a known fact that the whole Qur’aan was not revealed to Prophet Muhammad (sallallaahu `alayhi wa sallam) on a single night in Ramadaan. Ibn ‘Abbaas stated that the Qur’aan was first separated from its station in the upper heavens and placed in Bayt al-‘Izzah in the lowest heaven. One version states that this took place on the Night of Decree in Ramadaan. Had it been Allaah’s wish, the Qur’aan could then have been revealed as a whole to the Prophet (sallallaahu `alayhi wa sallam) in a single revelation.
This was the method by which all of the earlier books of revelation were sent down. But, Allaah chose to divide the revelation into two parts. The first revelation within the heavens represented an announcement to the inhabitants of the heavens that the final book of revelation was being sent down upon the last of the prophets.
From the lowest heaven sections of the Qur’aan were then taken down by the angel Jibreel to Prophet Muhammad (sallallaahu `alayhi wa sallam). This process of revelation continued over the twenty-three years of his prophethood. This revelation began with the first five verses of Soorah al-‘Alaq. These verses were revealed to the Prophet (sallallaahu `alayhi wa sallam) while he was on a spiritual retreat in the cave of Hiraa’ near Makkah. However, the first complete soorah to be revealed was Soorah al-Faatihah. The revelation of this portion of Qur’aan marked the beginning of the final phase of prophethood. The last soorah to be revealed was Soorah an-Nasr. This soorah was brought down in Minaa during the Farewell Hajj of the Prophet (sallallaahu `alayhi wa sallam), which took place at the end of the tenth year after the Hijrah. According to Ibn ‘Abbaas, the last verse to be revealed was verse 281 in Soorah al-Baqarah, the last of a series of verses dealing with interest. Allaah has referred to the second revelation in the following way:
“And (it is) a Qur’aan which I have divided into parts in order that you (Muhammad) may recite it to the people gradually, and I have revealed it by successive revelation.”(Soorah al-Israa’ 17:106)
1 Collected by al-Haakim in al-Mustadrak, vol. 2, pp. 665-6, no. 4216. Although the statement was not raised by Ibn ‘Abbaas to the Prophet (pbuh), it relates to the unseen world and could not have been made on the basis of reasoning. One of the narrators in the isnaad, al-A‘mash is reliable, but he is a mudallis, which means his reports cannot be accepted, unless he explicitly states that he heard the hadeeth from the person he attributed it to. He didn’t do that here, so the isnaad is weak.
2 Collected by an-Nasaa’ee in as-Sunan al-Kubraa, vol. 5, p. 7, no. 7991, and by at-Tabaraanee in al-Mu‘jam al-Kabeer. At-Tabaraanee’s isnaad includes a weak narrator. Nasaa’ee’s narrators are all reliable, but one of them is al-A‘mash. In this version also, he didn’t explicitly state that he heard the hadeeth from the person he attributed it to, so both isnaads are weak. However, an-Nasaa’ee collected two supporting narrations with authentic isnaads in the same chapter. They both mention the transferal of the Qur’aan to the lowest heaven during Laylatul-Qadr, but they don’t mention Bayt al-‘Izzah.
3 As-Suyootee says, “That the previous books were revealed all at once is well known from the statements of the scholars, such that it may practically be called ijmaa‘. However, I have seen some prominent contemporary scholars questioning this position, saying that there is no evidence for it and that, in fact, they were revealed over a period of time like the Qur’aan. I say the correct position is the first one. Among the evidences for that is the verse  from Soorah al-Furqaan [“And those who disbelieve say, ‘Why is the Qur’aan not revealed to him all at once?’ (It is revealed) thus so I may strengthen your heart by it, and I have arranged it in right order.”] “Ibn Abee Haatim reports from Sa‘eed ibn Jubayr who quotes Ibn ‘Abbaas that the Jews said, ‘O Muhammad, why wasn’t the Qur’aan revealed all at once, as the Torah was revealed to Moosaa? Then the verse (from Soorah al-Furqaan) was revealed.” He reported by another isnaad a similar report, except that the questioners were idolaters. He gathered similar reports on the authority of Qataadah and as-Suddee. “If you were to say that the Qur’aan is not explicit on this, and that even if these reports are authentic, these statements were made by disbelievers, I would reply as follows:“The fact that Allaah mentioned their objection without challenging the historical truth of their claim, but instead explained the wisdom behind (gradual revelation), is an indicator that their statement was factually correct. If the previous books had been revealed gradually, it would have been sufficient to refute them by saying that it was Allaah’s standard practice for the books He revealed to the previous prophets. That was how He responded to their objection, ‘What is it with this messenger that he eats food and walks in the markets?’ (25:7) [‘We never sent messengers before you who did not eat food and walk in the markets.’] (25:20).” Al-Itqaan fee ‘Uloom al-Qur’aan, vol. 1, p. 122.
4 Reported by ‘Aa’ishah and collected by al-Bukhaaree (Sahih Al-Bukhari, vol. 1, pp. 2-4, no. 3) and Muslim (Sahih Muslim, vol. 1, pp. 96-8, no. 301).
5 Collected by al-Bayhaqee in Dalaa’il an-Nuboowah and al-Waahidee in Asbaab an-Nuzool. As-Suyootee said its narrators were reliable but the isnaad is mursal. See al-Itqaan, vol. 1, pp.70-71.
6 That was Ibn ‘Abbaas’s opinion, as collected by Imaam Muslim (Sahih Muslim, vol. 4, p. 1554, nos. 7174-5). Other sahaabah had differing opinions. See al-Itqaan, vol. 1, pp. 77-81.
7 Collected by al-Bukhaaree (Sahih Al-Bukhari, vol. 6, p. 51, no. 67). This verse, “And guard yourselves against a day when you will be brought back to Allaah; then every soul will be paid in full what it earned, and they will not be wronged,” did not involve an addition to Islaamic legislation, therefore there is no contradiction between this report and the statement of Allaah in Soorah al-Maa’idah (5):3, revealed at the Farewell Hajj, “This day I have completed your deen for you.”