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.
bukhari:1972ʿAbd al-ʿAzīz b. ʿAbdullāh > Muḥammad b. Jaʿfar > Ḥumayd > Anas

Messenger of Allah ﷺ used to leave fasting in a certain month till we thought that he would not fast in that month, and he used to fast in another month till we thought he would not stop fasting at all in that month. And if one wanted to see him praying at night, one could see him (in that condition), and if one wanted to see him sleeping at night, one could see him (in that condition) too.  

البخاري:١٩٧٢حَدَّثَنِي عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ قَالَ حَدَّثَنِي مُحَمَّدُ بْنُ جَعْفَرٍ عَنْ حُمَيْدٍ

أَنَّهُ سَمِعَ أَنَسًا ؓ يَقُولُ كَانَ رَسُولُ اللَّهِ ﷺ يُفْطِرُ مِنَ الشَّهْرِ حَتَّى نَظُنَّ أَنْ لاَ يَصُومَ مِنْهُ وَيَصُومُ حَتَّى نَظُنَّ أَنْ لاَ يُفْطِرَ مِنْهُ شَيْئًا وَكَانَ لاَ تَشَاءُ تَرَاهُ مِنَ اللَّيْلِ مُصَلِّيًا إِلاَّ رَأَيْتَهُ وَلاَ نَائِمًا إِلاَّ رَأَيْتَهُ وَقَالَ سُلَيْمَانُ عَنْ حُمَيْدٍ أَنَّهُ سَأَلَ أَنَسًا فِي الصَّوْمِ  


See similar narrations below:

Collected by Bukhārī, Tirmidhī, Aḥmad, Ibn Ḥibbān, Bayhaqī
bukhari:1141ʿAbd al-ʿAzīz b. ʿAbdullāh > Muḥammad b. Jaʿfar > Ḥumayd > Anas

Sometimes Messenger of Allah ﷺ would not fast (for so many days) that we thought that he would not fast that month and he sometimes used to fast (for so many days) that we thought he would not leave fasting throughout that month and (as regards his prayer and sleep at night), if you wanted to see him praying at night, you could see him praying and if you wanted to see him sleeping, you could see him sleeping.  

البخاري:١١٤١حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ قَالَ حَدَّثَنِي مُحَمَّدُ بْنُ جَعْفَرٍ عَنْ حُمَيْدٍ

أَنَّهُ سَمِعَ أَنَسًا ؓ يَقُولُ كَانَ رَسُولُ اللَّهِ ﷺ يُفْطِرُ مِنَ الشَّهْرِ حَتَّى نَظُنَّ أَنْ لاَ يَصُومَ مِنْهُ وَيَصُومُ حَتَّى نَظُنَّ أَنْ لاَ يُفْطِرَ مِنْهُ شَيْئًا وَكَانَ لاَ تَشَاءُ أَنْ تَرَاهُ مِنَ اللَّيْلِ مُصَلِّيًا إِلاَّ رَأَيْتَهُ وَلاَ نَائِمًا إِلاَّ رَأَيْتَهُ  

تَابَعَهُ سُلَيْمَانُ وَأَبُو خَالِدٍ الأَحْمَرُ عَنْ حُمَيْدٍ
tirmidhi:769ʿAlī b. Ḥujr > Ismāʿīl b. Jaʿfar > Ḥumayd > Anas b. Mālik > Suʾil

Anas bin Malik was asked about the Prophet's fasting and he said: "He would fast during a month until we thought that he did not want to abstain from fasting during any of it. And, he would not fast during a month until we thought that he did not want to fast during any of it. (There was no time) that I wanted to see if he was performing Salat during the night, except that I would see him praying, nor to see him sleeping, except that I would see him sleeping."  

Abū ʿĪsá said that this Ḥadīth is Ḥasan-Ṣaḥīḥ.
الترمذي:٧٦٩حَدَّثَنَا عَلِيُّ بْنُ حُجْرٍ حَدَّثَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ عَنْ حُمَيْدٍ عَنْ أَنَسِ بْنِ مَالِكٍ أَنَّهُ سُئِلَ

عَنْ صَوْمِ النَّبِيِّ ﷺ قَالَ كَانَ يَصُومُ مِنَ الشَّهْرِ حَتَّى نَرَى أَنَّهُ لاَ يُرِيدُ أَنْ يُفْطِرَ مِنْهُ وَيُفْطِرُ حَتَّى نَرَى أَنَّهُ لاَ يُرِيدُ أَنْ يَصُومَ مِنْهُ شَيْئًا وَكُنْتَ لاَ تَشَاءُ أَنْ تَرَاهُ مِنَ اللَّيْلِ مُصَلِّيًا إِلاَّ رَأَيْتَهُ مُصَلِّيًا وَلاَ نَائِمًا إِلاَّ رَأَيْتَهُ نَائِمًا  

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ
ahmad:13473Muḥammad b. ʿAbdullāh > Ḥumayd > Anas b. Mālik > Suʾil

Anas bin Malik was asked about the Prophet's fasting and he said: "He would fast during a month until we thought that he did not want to abstain from fasting during any of it. And, he would not fast during a month until we thought that he did not want to fast during any of it. (There was no time) that I wanted to see if he was performing Salat during the night, except that I would see him praying, nor to see him sleeping, except that I would see him sleeping." (Using translation from Tirmidhī 769)   

أحمد:١٣٤٧٣حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللهِ حَدَّثَنَا حُمَيْدٌ عَنْ أَنَسِ بْنِ مَالِكٍ أَنَّهُ سُئِلَ

عَنْ صَلَاةِ النَّبِيِّ ﷺ وَصَوْمِهِ تَطَوُّعًا قَالَ كَانَ يَصُومُ مِنَ الشَّهْرِ حَتَّى نَقُولَ مَا يُرِيدُ أَنْ يُفْطِرَ مِنْهُ شَيْئًا وَيُفْطِرُ حَتَّى نَقُولَ مَا يُرِيدُ أَنْ يَصُومَ مِنْهُ شَيْئًا وَمَا كُنَّا نَشَاءُ أَنْ نَرَاهُ مِنَ اللَّيْلِ مُصَلِّيًا إِلَّا رَأَيْنَاهُ وَلَا نَرَاهُ نَائِمًا إِلَّا رَأَيْنَاهُ  

ذِكْرُ خَبَرٍ ثَانٍ يُصَرِّحُ بِصِحَّةِ مَا ذَكَرْنَاهُ

ibnhibban:2618Muḥammad b. ʿAbd al-Raḥman al-Sāmī > Yaḥyá b. Ayyūb al-Maqābirī > Ismāʿīl b. Jaʿfar > Ḥumayd al-Ṭawīl > Suʾil Anas b. Mālik

Anas bin Malik was asked about the Prophet's fasting and he said: "He would fast during a month until we thought that he did not want to abstain from fasting during any of it. And, he would not fast during a month until we thought that he did not want to fast during any of it. (There was no time) that I wanted to see if he was performing Salat during the night, except that I would see him praying, nor to see him sleeping, except that I would see him sleeping." (Using translation from Tirmidhī 769)  

ابن حبّان:٢٦١٨أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الرَّحْمَنِ السَّامِيُّ قَالَ حَدَّثَنَا يَحْيَى بْنُ أَيُّوبَ الْمَقَابِرِيُّ قَالَ حَدَّثَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ قَالَ أَخْبَرَنِي حُمَيْدٌ الطَّوِيلُ قَالَ سُئِلَ أَنَسُ بْنُ مَالِكٍ

عَنْ صَوْمِ النَّبِيِّ ﷺ قَالَ «كَانَ يَصُومُ مِنَ الشَّهْرِ حَتَّى نَرَى أَنَّهُ لَا يُرِيدُ أَنْ يُفْطِرَ مِنْهُ شَيْئًا وَيُفْطِرُ مِنَ الشَّهْرِ حَتَّى نَرَى أَنَّهُ لَا يُرِيدُ أَنْ يَصُومَ مِنْهُ شَيْئًا وَكُنْتَ لَا تَشَاءُ أَنْ تَرَاهُ مِنَ اللَّيْلِ مُصَلِّيًا إِلَّا رَأَيْتَهُ مُصَلِّيًا وَلَا نَائِمًا إِلَّا رَأَيْتَهُ»  

bayhaqi:4734Abū Ṭāhir al-Faqīh from Aṣlih > Abū al-Faḍl ʿAbdūs b. al-Ḥusayn b. Manṣūr al-Naysābūrī > Abū Ḥātim al-Rāzī > Muḥammad b. ʿAbdullāh al-Anṣārī > Ḥumayd > Suʾil Anas

Anas bin Malik was asked about the Prophet's fasting and he said: "He would fast during a month until we thought that he did not want to abstain from fasting during any of it. And, he would not fast during a month until we thought that he did not want to fast during any of it. (There was no time) that I wanted to see if he was performing Salat during the night, except that I would see him praying, nor to see him sleeping, except that I would see him sleeping." (Using translation from Tirmidhī 769)   

البيهقي:٤٧٣٤أَخْبَرَنَا أَبُو طَاهِرٍ الْفَقِيهُ مِنْ أَصْلِهِ أنبأ أَبُو الْفَضْلِ عَبْدُوسُ بْنُ الْحُسَيْنِ بْنِ مَنْصُورٍ النَّيْسَابُورِيُّ ثنا أَبُو حَاتِمٍ الرَّازِيُّ ثنا مُحَمَّدُ بْنُ عَبْدِ اللهِ الْأَنْصَارِيُّ حَدَّثَنِي حُمَيْدٌ قَالَ سُئِلَ أَنَسٌ

عَنْ صَلَاةِ النَّبِيِّ ﷺ وَصَوْمِهِ تَطَوُّعًا قَالَ كَانَ يَصُومُ مِنَ الشَّهْرِ حَتَّى نَقُولَ مَا يُرِيدُ أَنْ يُفْطِرَ مِنْهُ شَيْئًا وَيُفْطِرُ مِنَ الشَّهْرِ حَتَّى نَقُولَ مَا يُرِيدُ أَنْ يَصُومَ مِنْهُ شَيْئًا وَمَا كُنَّا نَشَاءُ أَنْ نَرَاهُ مِنَ اللَّيْلِ مُصَلِّيًا إِلَّا رَأَيْنَاهُ وَلَا نَرَاهُ نَائِمًا إِلَّا رَأَيْنَاهُ