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:20:2 –

We have not sent down to you the Qur'an that you be distressed  

We have not revealed the Qur’ān to you, O Muhammad (s), that you should be miserable, that you should toil because of what you used to do after it was revealed ˹to you˺, in the way of long vigils performing night prayers; in other words, so unburden your soul;
القرآن:٢٠:٢ –

مَا أَنْزَلْنَا عَلَيْكَ الْقُرْآنَ لِتَشْقَىٰ  

{ما أنزلنا عليك القرآن} يا محمد {لتشقى} لتتعب بما فعلت بعد نزوله من طول قيامك بصلاة الليل أي خفف عن نفسك.

See similar narrations below:

Collected by Qurʾān
quran:76:23 –

Indeed, it is We who have sent down to you, ˹O Muhammad˺, the Qur'an progressively.  

Assuredly We (nahnu reiterates the subject of innā, ‘assuredly, for the purpose of emphasis; alternatively it is a separating pronoun) have revealed the Qur’ān to you as a gradual revelation (tanzīlan is the predicate of inna, ‘assuredly’), in other words, We have divided it into parts instead of not revealing it all at once.
القرآن:٧٦:٢٣ –

إِنَّا نَحْنُ نَزَّلْنَا عَلَيْكَ الْقُرْآنَ تَنْزِيلًا  

{إنا نحن} تأكيد لاسم إن أو فصل {نزلنا عليك القرآن تنزيلا} خبر إن أي فصلناه ولم ننزله جملة واحدة.