Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
quran:75:17

Indeed, upon Us is its collection ˹in your heart˺ and ˹to make possible˺ its recitation.  

Assuredly it is for Us to bring it together, in your breast, and to recite it, your reciting of it, that is, its flowing off your tongue.
القرآن:٧٥:١٧

إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ  

{إن علينا جمعه} في صدرك {وقرآنه} قراءتك إياه أي جريانه على لسانك.

See similar narrations below:

Collected by Bukhārī

The Prophet's ﷺ eagerness to memorize the Quran and the reassurance of its preservation by Allah

bukhari:5Mūsá b. Ismāʿīl > Abū ʿAwānah > Mūsá b. Abū ʿĀʾishah > Saʿīd b. Jubayr > Ibn ʿAbbās

˹regarding˺ the statement of Allah "Move not your tongue concerning (the Quran) to make haste therewith." (Qiyāmah 75:16), he said: the Messenger of Allah ﷺ used to bear the revelation with great trouble and used to move his lips ˹quickly˺ (along with the inspiration being revealed so that he would not forget).

Ibn ʿAbbās ˹moved his lips saying˺: I am moving my lips in front of you as the Messenger of Allah ﷺ used to move his." Saʿīd said: I am moving my lips, as I saw Ibn ʿAbbās moving his, while he was moving his own his lips.

˹The narrator added˺ So Allah revealed: "Move not your tongue with it, ˹O Muhammad˺, to hasten with it. Indeed, upon Us is its collection and its recitation." (Qiyāmah 75:16-17). He said: Its collection meaning in your heart so you can recite it. "So when We have recited it ˹through Gabriel˺, then follow its recitation." (Qiyāmah 75:18) He said: listen ˹attentively˺ and remain silent. "Then upon Us is its clarification." (Qiyāmah 75:19) Then upon us is that you recite it. Afterwards, the Messenger of Allah ﷺ used to listen ˹attentively˺ to Jibrīl (Gabriel) whenever he came, and after Jibrīl left, he used to recite it as he had recited it.  

البخاري:٥حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ قَالَ حَدَّثَنَا أَبُو عَوَانَةَ قَالَ حَدَّثَنَا مُوسَى بْنُ أَبِي عَائِشَةَ قَالَ حَدَّثَنَا سَعِيدُ بْنُ جُبَيْرٍ عَنِ ابْنِ عَبَّاسٍ

فِي قَوْلِهِ تَعَالَى {لاَ تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِهِ} قَالَ كَانَ رَسُولُ اللَّهِ ﷺ يُعَالِجُ مِنَ التَّنْزِيلِ شِدَّةً وَكَانَ مِمَّا يُحَرِّكُ شَفَتَيْهِ.

فَقَالَ ابْنُ عَبَّاسٍ فَأَنَا أُحَرِّكُهُمَا لَكُمْ كَمَا كَانَ رَسُولُ اللَّهِ ﷺ يُحَرِّكُهُمَا. وَقَالَ سَعِيدٌ أَنَا أُحَرِّكُهُمَا كَمَا رَأَيْتُ ابْنَ عَبَّاسٍ يُحَرِّكُهُمَا فَحَرَّكَ شَفَتَيْهِ.

فَأَنْزَلَ اللَّهُ تَعَالَى {لاَ تُحَرِّكْ بِهِ لِسَانَكَ لِتَعْجَلَ بِهِ* إِنَّ عَلَيْنَا جَمْعَهُ وَقُرْآنَهُ} قَالَ جَمْعُهُ لَهُ فِي صَدْرِكَ وَتَقْرَأَهُ {فَإِذَا قَرَأْنَاهُ فَاتَّبِعْ قُرْآنَهُ} قَالَ فَاسْتَمِعْ لَهُ وَأَنْصِتْ {ثُمَّ إِنَّ عَلَيْنَا بَيَانَهُ} ثُمَّ إِنَّ عَلَيْنَا أَنْ تَقْرَأَهُ. فَكَانَ رَسُولُ اللَّهِ ﷺ بَعْدَ ذَلِكَ إِذَا أَتَاهُ جِبْرِيلُ اسْتَمَعَ فَإِذَا انْطَلَقَ جِبْرِيلُ قَرَأَهُ النَّبِيُّ ﷺ كَمَا قَرَأَهُ.