Narrated Musa bin Abi 'Aisha:

Sa'id bin Jubair reported from Ibn 'Abbas (regarding the explanation of the Verse: 'Do not move your tongue concerning (the Qur'an) to make haste therewith) . He said, "The Prophet used to undergo great difficulty in receiving the Divine Inspiration and used to move his lips.' Ibn 'Abbas said (to Sa'id), "I move them (my lips) as Allah's Apostle used to move his lips." And Said said (to me), "I move my lips as I saw Ibn 'Abbas moving his lips," and then he moved his lips. So Allah revealed:-- '(O Muhammad!) Do not move your tongue concerning (the Qur'an) to make haste therewith. It is for Us to collect it and give you (O Muhammad) the ability to recite it. (i.e., to collect it in your chest and then you recite it).' (75.16-17) But when We have recited it, to you (O Muhammad through Gabriel) then follow you its recital.' (75.18) This means, "You should listen to it and keep quiet and then it is upon Us to make you recite it." The narrator added, "So Allah's Apostle used to listen whenever Gabriel came to him, and when Gabriel left, the Prophet would recite the Qur'an as Gabriel had recited it to him."

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ مُوسَى بْنِ أَبِي عَائِشَةَ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، فِي قَوْلِهِ تَعَالَى {لاَ تُحَرِّكْ بِهِ لِسَانَكَ} قَالَ كَانَ النَّبِيُّ ﷺ يُعَالِجُ مِنَ التَّنْزِيلِ شِدَّةً، وَكَانَ يُحَرِّكُ شَفَتَيْهِ ـ فَقَالَ لِي ابْنُ عَبَّاسٍ أُحَرِّكُهُمَا لَكَ كَمَا كَانَ رَسُولُ اللَّهِ ﷺ يُحَرِّكُهُمَا فَقَالَ سَعِيدٌ أَنَا أُحَرِّكُهُمَا كَمَا كَانَ ابْنُ عَبَّاسٍ يُحَرِّكُهُمَا فَحَرَّكَ شَفَتَيْهِ ـ فَأَنْزَلَ اللَّهُ عَزَّ وَجَلَّ {لاَ تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِهِ * إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ} قَالَ جَمْعُهُ فِي صَدْرِكَ ثُمَّ تَقْرَؤُهُ. {فَإِذَا قَرَأْنَاهُ فَاتَّبِعْ قُرْآنَهُ} قَالَ فَاسْتَمِعْ لَهُ وَأَنْصِتْ ثُمَّ إِنَّ عَلَيْنَا أَنْ تَقْرَأَهُ. قَالَ فَكَانَ رَسُولُ اللَّهِ ﷺ إِذَا أَتَاهُ جِبْرِيلُ ـ عَلَيْهِ السَّلاَمُ ـ اسْتَمَعَ فَإِذَا انْطَلَقَ جِبْرِيلُ قَرَأَهُ النَّبِيُّ ﷺ كَمَا أَقْرَأَهُ.