ثُمَّ إِنَّ عَلَيْنَا بَيَانَهُ ﴿١٩﴾

Then it is for Us to make it clear.

meaning, `after memorizing it and reciting it, We will explain it to you, clarify it and inspire you with its meaning according to what We intended and legislated.'

Imam Ahmad recorded from Ibn `Abbas that he said that

the Messenger of Allah used to struggle very hard to grasp the revelation and he used to move his lips (rapidly with the recitation).

The narrator, Sa`id, then said, "Ibn `Abbas said to me, `I will move my lips like the Messenger of Allah used to move his lips (in order to show you).'''

Then, the sub narrator said, "And Sa`id said to me, `I will move my lips like I saw Ibn `Abbas moving his lips (in order to show you).'''

Then Allah revealed,

لَا تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِه

إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ

Move not your tongue concerning to make haste therewith. It is for Us to collect it and that it be recited.)

Ibn `Abbas said,

"This means He will collect it in his chest to recite it.

فَإِذَا قَرَأْنَاهُ فَاتَّبِعْ قُرْآنَهُ

And when We have recited it to you, then follow its recitation.

meaning, listen to it and pay attention.

ثُمَّ إِنَّ عَلَيْنَا بَيَانَهُ

Then it is for Us to make it clear (to you).

So after this, when Jibril would leave, he would recite it as Jibril had taught him to recite it.''

This has also been recorded by Al-Bukhari and Muslim.

Al-Bukhari's wording says,

"So whenever Jibril would come to him he would be silent, and when Jibril had left he would recite it just as Allah, the Mighty and Sublime had promised him.''