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.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
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:5 – Mūsá 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:٥ – حَدَّثَنَا 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.