How can the statement of Ibn 'Abbas regarding the Qur'an's descent in its entirety from Bayt al-'Izzah to the lowest heaven be reconciled with its piecemeal revelation by Gabriel from God to the Prophet, may God's prayers and peace be upon him?

The Holy Quran was revealed by Allah Almighty through Gabriel (peace be upon him) to the Prophet Muhammad (peace be upon him) in stages. The Holy Quran affirms that Gabriel heard it directly from Allah and brought it down to the heart of the Prophet with Allah's permission, and it is a revelation from the Lord of the Worlds.

It has been confirmed by the Salaf, including Shaykh al-Islam Ibn Taymiyyah and Ibn Hajar, that Gabriel received the Quran from Allah Almighty, and that the Prophet (peace be upon him) heard it from Gabriel.

There are narrations from Ibn Abbas (may Allah be pleased with them both) indicating that the Quran was revealed all at once from the Preserved Tablet (Al-Lawh Al-Mahfuz) to Bayt Al-Izzah (House of Glory) in the lowest heaven on the Night of Qadr in the month of Ramadan. Then, it was revealed gradually to the Prophet (peace be upon him) over twenty-three years, according to events and occurrences.

This does not contradict Gabriel hearing the Quran from Allah, as the Quran was written in the Preserved Tablet and in honored scriptures before its revelation. Then Gabriel brought it down from Allah, and it was revealed all at once to Bayt Al-Izzah, then it was gradually revealed to the Prophet (peace be upon him).