We went to ʿAbdullah in the morning and a man said, "Yesterday I recited all the Mufassal Suras." On that ʿAbdullah said, "That is very quick, and we have the (Prophet's) recitation, and I remember very well the recitation of those Suras which the Prophet ﷺ used to recite, and they were eighteen Suras from the Mufassal, and two Suras from the Suras that start with Ha Mim.  

سَمِعْنَا الْقِرَاءَةَ وَإِنِّي لأَحْفَظُ الْقُرَنَاءَ الَّتِي كَانَ يَقْرَأُ بِهِنَّ النَّبِيُّ ﷺ ثَمَانِيَ عَشْرَةَ سُورَةً مِنَ الْمُفَصَّلِ وَسُورَتَيْنِ مِنْ آلِ حم  

Regarding His (Allah's) Statement:-- 'Move not your tongue concerning (the Qur'an) to make haste therewith.' (75.16) And whenever Gabriel descended to Messenger of Allah ﷺ with the Divine Inspiration, Messenger of Allah ﷺ used to move his tongue and lips, and that used to be hard for him, and one could easily recognize that he was being inspired Divinely. So Allah revealed the Verse which occurs in the Surah starting with "I do swear by the Day of Resurrection.' (75.1) i.e. 'Move not your tongue concerning (the Qur'an) to make haste then with. It is for Us to collect it (in your mind) (O Muhammad) an give you the ability to recite it 'by heart.' (75.16-17) which means: It is for us to collect it (in your mind) and give you the ability to recite it by heart. And when We have recited it to you (O Muhammad) through Gabriel then follow you its recital. (75.18) means: 'When We reveal it (the Qur'an) to you, Listen to it.' for then: It is for Us to explain it and make it clear to you' (75.19) i.e. It is up to Us to explain it through your tongue. So, when Gabriel came to him, Messenger of Allah ﷺ would listen to him attentively, and as soon as Gabriel left, he would recite the Revelations, as Allah had promised him.  

فِي قَوْلِهِ {لاَ تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِهِ} قَالَ كَانَ رَسُولُ اللَّهِ ﷺ إِذَا نَزَلَ جِبْرِيلُ بِالْوَحْىِ وَكَانَ مِمَّا يُحَرِّكُ بِهِ لِسَانَهُ وَشَفَتَيْهِ فَيَشْتَدُّ عَلَيْهِ وَكَانَ يُعْرَفُ مِنْهُ فَأَنْزَلَ اللَّهُ الآيَةَ الَّتِي فِي {لاَ أُقْسِمُ بِيَوْمِ الْقِيَامَةِ} {لاَ تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِهِ * إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ * فَإِذَا قَرَأْنَاهُ فَاتَّبِعْ قُرْآنَهُ} فَإِذَا أَنْزَلْنَاهُ فَاسْتَمِعْ {ثُمَّ إِنَّ عَلَيْنَا بَيَانَهُ} قَالَ إِنَّ عَلَيْنَا أَنْ نُبَيِّنَهُ بِلِسَانِكَ قَالَ وَكَانَ إِذَا أَتَاهُ جِبْرِيلُ أَطْرَقَ فَإِذَا ذَهَبَ قَرَأَهُ كَمَا وَعَدَهُ اللَّهُ