First Opinion:

The Lajnah Daa’imah stated:

“The Qur’an as a whole was sent down to Bayt Al-`Izzah (the House of Glory) in the lowest heaven during Laylat-ul-Qadr in Ramadan. Allah (Exalted be He) says:

The month of Ramadan in which was revealed the Qur’ân, a guidance for mankind

He (Exalted be He) also says:

Verily, We have sent it (this Qur’ân) down in the night of Al-Qadr (Decree).

Then the Qur’an was revealed to the Prophet (peace be upon him) in portions according to the situations and conditions throughout twenty-three years.”

[Reference]

This is the opinion of the majority of the scholars.

Second Opinion:

The first part of the Quran [i.e the beginning of Surah Iqra] was revealed unto the Prophet sallahu alayhi wa salam in the Month of Ramadan on Laylatul Qadr, then the rest of the Quran was revealed to Him sallahu alayhi wa salam at different timings. And they don’t see it correct to say that the Whole Quran was sent down all at once to Bayt Al-`Izzah (the House of Glory) in the lowest heaven.

This opinion is ascribed to al-Imam Sha’bee rahimahullah and from the contemporary scholars Ash-Shaykh Muhammad bin Saalih al-Uthaymeen rahimahullah and Shaykh Saalih al-Fawzaan hafidaho-Allah.

Note: Both opinions are regarded as opinions of Ahlus Sunnah since both groups hold that Jibreel would hear the revelation from Allaah as it is being revealed and upon its occurrence, then convey it directly to the Prophet sallahu alayhi wa salam. Also, they don’t deem it correct to say Jibreel took the revelation from what was sent down to the lowest heaven or from was written in the preserved tablet. Rather, Jibreel would hear it from Allaah while the verses were being revealed throughout the twenty three year period.

Mentioned by

AbdulFattaah Bin Uthman
Abu Fajr