'Abdullah b. 'Amr (Allah be pleased with them) reported that the Messenger of Allah (ﷺ) said to me! 'Abdullah b. 'Amr, it has been conveyed to me that you observe fast during the day and stand in prayer during the whole night. Don't do that, for your body has a share of its own in you, your eye has a share of its own in you, your wife has a share of her own in you. Observe fast and break it too. Fast for three days in every month and that is a prepetual fasting. I said! Messenger of Allah, I have got strength enough (to do more than this), whereupon he said:Then observe the fast of David (peace be upon him). Observe fast one day and break it (on the other) day. And he ('Abdullah b. 'Amr) used to say: Would that I had availed myself of this concession.
وَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، وَمُحَمَّدُ بْنُ حَاتِمٍ، جَمِيعًا عَنِ ابْنِ مَهْدِيٍّ، - قَالَ زُهَيْرٌ حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، - حَدَّثَنَا سَلِيمُ بْنُ حَيَّانَ، حَدَّثَنَا سَعِيدُ بْنُ مِينَاءَ، قَالَ قَالَ عَبْدُ اللَّهِ بْنُ عَمْرٍو قَالَ لِي رَسُولُ اللَّهِ صلى الله عليه وسلم " يَا عَبْدَ اللَّهِ بْنَ عَمْرٍو بَلَغَنِي أَنَّكَ تَصُومُ النَّهَارَ وَتَقُومُ اللَّيْلَ فَلاَ تَفْعَلْ فَإِنَّ لِجَسَدِكَ عَلَيْكَ حَظًّا وَلِعَيْنِكَ عَلَيْكَ حَظًّا وَإِنَّ لِزَوْجِكَ عَلَيْكَ حَظًّا صُمْ وَأَفْطِرْ صُمْ مِنْ كُلِّ شَهْرٍ ثَلاَثَةَ أَيَّامٍ فَذَلِكَ صَوْمُ الدَّهْرِ " . قُلْتُ يَا رَسُولَ اللَّهِ إِنَّ بِي قُوَّةً . قَالَ " فَصُمْ صَوْمَ دَاوُدَ - عَلَيْهِ السَّلاَمُ - صُمْ يَوْمًا وَأَفْطِرْ يَوْمًا " . فَكَانَ يَقُولُ يَا لَيْتَنِي أَخَذْتُ بِالرُّخْصَةِ .
Muslim
The Book of Fasting • Hadith 249