[saimma]

Narrated Ibn Abbas (Radi-Allahu 'anhu):

(as regards) Allah's Statement:

"Move not your tongue concerning (the Quran) to make haste therewith."
(75.16)

When Gabriel revealed the Divine Inspiration to Allah's Apostle (Sallallahu
'Alaihi Wa Sallam), he (Allah's Apostle) moved his tongue and lips, and
that state used to be very hard for him, and that movement indicated that
revelation was taking place. So Allah revealed in Surat Al-Qiyama which
begins:

'I do swear by the Day of Resurrection...' (75) the Verses:

'Move not your tongue concerning (the Quran) to make haste therewith. It is
for Us to collect it (Quran) in your mind, and give you the ability to
recite it by heart.' (75.16-17) Ibn Abbas added: 'It is for Us to collect
it (Qur'an) (in your mind), and give you the ability to recite it by heart'
means, "When We reveal it, listen. Then it is for Us to explain it," which
means, 'It is for us to explain it through your tongue." So whenever
Gabriel came to Allah's Apostle (Sallallahu 'Alaihi Wa Sallam) he would
keep quiet (and listen), and when the Angel left, the Prophet (Sallallahu
'Alaihi Wa Sallam) would recite that revelation as Allah promised him.

Bukhari Vol. 6 : No. 451