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:73:20 –

Indeed, your Lord knows, ˹O Muhammad˺, that you stand ˹in prayer˺ almost two thirds of the night or half of it or a third of it, and ˹so do˺ a group of those with you. And Allah determines ˹the extent of˺ the night and the day. He has known that you ˹Muslims˺ will not be able to do it and has turned to you in forgiveness, so recite what is easy ˹for you˺ of the Qur'an. He has known that there will be among you those who are ill and others traveling throughout the land seeking ˹something˺ of the bounty of Allah and others fighting for the cause of Allah. So recite what is easy from it and establish prayer and give zakah and loan Allah a goodly loan. And whatever good you put forward for yourselves - you will find it with Allah. It is better and greater in reward. And seek forgiveness of Allah. Indeed, Allah is Forgiving and Merciful.  

Assuredly your Lord knows that you stand vigil less than two thirds of the night, or ˹at times˺ a half of it or a third of it (if read wa-nisfihi wa-thuluthihi, then these constitute a supplement to thuluthay, ‘two thirds’; if read wa-nisfahu wa-thuluthahu, then a supplement to adnā, ‘less than’) — his keeping vigil in the way mentioned is in accordance with what was enjoined on him at the beginning of this sūra — along with a group of those with you (wa-tā’ifatun mina’lladhīna ma‘aka constitutes a supplement to the subject ˹of the verb˺ taqūmu, ‘you stand vigil’, but it may also constitute, although it is not certain, a separating clause). The keeping vigil by some of his companions in this way indicates their emulation of him. Some of them could not tell how much of the night they had spent in prayer and how much of it had remained, and would therefore keep vigil all night as a precaution; and so they used to keep vigil ˹in this way˺ for a whole year or more with their feet swollen, until God alleviated matters for them. He, exalted be He, says: and God keeps measures, He keeps count of, the night and the day. He knows that (an: softened in place of the hardened form, its subject having been omitted, that is to say, annahu) you will not be able to keep count of it, that is, the ˹length of the˺ night, so that you may perform the vigil at the time in which it is required unless you stay up all night, which is hard on you, and so He has relented to you, making you revert to what is easier. So recite as much as is feasible of the Qur’ān, during prayer, by performing as much prayer as is feasible. He knows that (an: softened in place of the hardened form, that is to say, annahu) some of you will be sick, while others will be travelling in the land, seeking the bounty of God, seeking of His provision through commerce and otherwise, and others will be fighting in the way of God: for each of the three groups mentioned the keeping of nightly vigil is hard, and so God has alleviated things for them by ˹enjoining on them˺ what is feasible. Later this was abrogated by the five ˹daily˺ prayers. So recite as much as is feasible of it (as ˹explained˺ above) and perform, obligatory, prayer and pay alms and lend God, by expending in the way of good in addition to what is due from your wealth ˹as alms˺, a goodly loan, out of the goodness of ˹your˺ hearts. For whatever good you send ahead for ˹the sake of˺ your souls, you will find that, with God, it will be better, than what you left behind (huwa khayran: huwa is for separation; what follows it ˹khayran, ‘better’˺ is comparable to a definite, even if it is not ˹actually˺ so, on account of the impossibility of it being given ˹the al- of˺ definition) and greater in terms of reward. And seek forgiveness from God; assuredly God is Forgiving, Merciful, to believers. Mecca, consisting of 56 verses.
القرآن:٧٣:٢٠ –

إِنَّ رَبَّكَ يَعْلَمُ أَنَّكَ تَقُومُ أَدْنَىٰ مِنْ ثُلُثَيِ اللَّيْلِ وَنِصْفَهُ وَثُلُثَهُ وَطَائِفَةٌ مِنَ الَّذِينَ مَعَكَ ۚ وَاللَّهُ يُقَدِّرُ اللَّيْلَ وَالنَّهَارَ ۚ عَلِمَ أَنْ لَنْ تُحْصُوهُ فَتَابَ عَلَيْكُمْ ۖ فَاقْرَءُوا مَا تَيَسَّرَ مِنَ الْقُرْآنِ ۚ عَلِمَ أَنْ سَيَكُونُ مِنْكُمْ مَرْضَىٰ ۙ وَآخَرُونَ يَضْرِبُونَ فِي الْأَرْضِ يَبْتَغُونَ مِنْ فَضْلِ اللَّهِ ۙ وَآخَرُونَ يُقَاتِلُونَ فِي سَبِيلِ اللَّهِ ۖ فَاقْرَءُوا مَا تَيَسَّرَ مِنْهُ ۚ وَأَقِيمُوا الصَّلَاةَ وَآتُوا الزَّكَاةَ وَأَقْرِضُوا اللَّهَ قَرْضًا حَسَنًا ۚ وَمَا تُقَدِّمُوا لِأَنْفُسِكُمْ مِنْ خَيْرٍ تَجِدُوهُ عِنْدَ اللَّهِ هُوَ خَيْرًا وَأَعْظَمَ أَجْرًا ۚ وَاسْتَغْفِرُوا اللَّهَ ۖ إِنَّ اللَّهَ غَفُورٌ رَحِيمٌ  

{إن ربك يعلم أنك تقوم أَدنى} أقل {من ثلثي الليل ونصفِه وثلثِه} بالجر عطف على ثلثي وبالنصب على أدنى وقيامه كذلك نحو ما أمر به أول السورة {وطائفة من الذين معك} عطف على ضمير تقوم وجاز من غير تأكيد للفصل وقيام طائفة من أصحابه كذلك للتأسي به ومنهم من كان لا يدري كم صلّى من الليل وكم بقي منه فكان يقوم الليل كله احتياطا فقاموا حتى انتفخت أقدامهم سنة أو أكثر فخفف عنهم قال تعالى: {والله يقدر} يحصي {الليل والنهار علم أن} مخففة من الثقيلة واسمها محذوف، أي أنه {لن تحصوه} أي الليل لتقوموا فيما يجب القيام فيه إلا بقيام جميعه وذلك يشق عليكم {فتاب عليكم} رجع بكم إلى التخفيف {فاقرؤوا ما تيسر من القرآن} في الصلاة بأن تصلوا ما تيسر {علم أن} مخففة من الثقيلة، أي أنه {سيكون منكم مرضى وآخرون يضربون في الأرض} يسافرون {يبتغون من فضل الله} يطلبون من رزقه بالتجارة وغيرها {وآخرون يقاتلون في سبيل الله} وكل من الفرق الثلاثة يشق عليهم ما ذكر في قيام الليل فخفف عنهم بقيام ما تيسر منه ثم نسخ ذلك بالصلوات الخمس {فاقرؤوا ما تيسر منه} كما تقدم {وأقيموا الصلاة} المفروضة {وآتوا الزكاة وأقرضوا الله} بأن تنفقوا ما سوى المفروض من المال في سبيل الخير {قرضا حسنا} عن طيب قلب {وما تقدموا لأنفسكم من خير تجدوه عند الله هو خيرا} مما خلفتم وهو فصل وما بعده وإن لم يكن معرفة يشبهها لامتناعه من التعريف {وأعظم أجرا واستغفروا الله إن الله غفور رحيم} للمؤمنين.