"I entered upon 'Abdullah bin 'Amr and said: O uncle, tell me what the Messenger of Allah said to you. He said: O son of my brother, I had resolved to strive very hard until I said: I will fast for the rest of my life and I will read the whole Quran every day and night. The Messenger of Allah heard about that, and came in to me in my house, and said: I have heard that you said, I will fast for a lifetime and will read the Quran. I said: I did say that, O Messenger of Allah. He said; Do not do that. Fast three days of each month. I said: I am able to do more than that. He said: fast two days of each week, Monday and Thursday. I said: I am able to do more than that. He said; Observe the fast of Dawud, peace be upon him, for it is the best kind of fasting before Allah; one day fasting, and one day not fasting. And when he made a promise he did not break it, and when he met (the enemy in battle) he did not flee." 'Ata said: "someone who heard him told me that Ibn 'Umar (said) that the Prophet said: 'Whoever fasts every day of his life, then he has not fasted."  

لَكَ رَسُولُ اللَّهِ ﷺ قَالَ يَا ابْنَ أَخِي إِنِّي كُنْتُ أَجْمَعْتُ عَلَى أَنْ أَجْتَهِدَ اجْتِهَادًا شَدِيدًا حَتَّى قُلْتُ لأَصُومَنَّ الدَّهْرَ وَلأَقْرَأَنَّ الْقُرْآنَ فِي كُلِّ يَوْمٍ وَلَيْلَةٍ فَسَمِعَ بِذَلِكَ رَسُولُ اللَّهِ ﷺ فَأَتَانِي حَتَّى دَخَلَ عَلَىَّ فِي دَارِي فَقَالَ بَلَغَنِي أَنَّكَ قُلْتَ لأَصُومَنَّ الدَّهْرَ وَلأَقْرَأَنَّ الْقُرْآنَ فَقُلْتُ قَدْ قُلْتُ ذَلِكَ يَا رَسُولَ اللَّهِ قَالَ فَلاَ تَفْعَلْ صُمْ مِنْ كُلِّ شَهْرٍ ثَلاَثَةَ أَيَّامٍ قُلْتُ إِنِّي أَقْوَى عَلَى أَكْثَرَ مِنْ ذَلِكَ قَالَ فَصُمْ مِنَ الْجُمُعَةِ يَوْمَيْنِ الاِثْنَيْنِ وَالْخَمِيسَ قُلْتُ فَإِنِّي أَقْوَى عَلَى أَكْثَرَ مِنْ ذَلِكَ قَالَ فَصُمْ صِيَامَ دَاوُدَ عَلَيْهِ السَّلاَمُ فَإِنَّهُ أَعْدَلُ الصِّيَامِ عِنْدَ اللَّهِ يَوْمًا صَائِمًا وَيَوْمًا مُفْطِرًا وَإِنَّهُ كَانَ إِذَا وَعَدَ لَمْ يُخْلِفْ وَإِذَا لاَقَى لَمْ يَفِرَّ  

[Machine] "Abdullah entered my house, the Messenger of Allahﷺ and said, 'Did I not inform you that you should recite the Quran every day and night?' So, recite it every month.' I said, 'I am capable of doing more than that.' He said, 'Then recite it every half month.' I said, 'I am capable of doing more than that.' He said, 'Then recite it every seven days, but do not increase it.' And he informed me that I fast the entire lifetime. I said, 'I do fast, O Messenger of Allah.' He said, 'Fast for three days every month.' I said, 'I am capable of doing more than that.' He said, 'Fast for two days every week.' I said, 'I am capable of doing more than that.' He said, 'Fast as Dawood (David) fasted, one day on and one day off, for it is the most just fast in the sight of Allah and he did not break his promise nor run away when he met with someone.'"  

عَبْدُ اللهِ دَخَلَ عَلَيَّ رَسُولُ اللهِ ﷺ بَيْتِي فَقَالَ أَلَمْ أُخْبَرْ أَنَّكَ تَقْرَأُ الْقُرْآنَ فِي كُلِّ يَوْمٍ وَلَيْلَةٍ؟ فَاقْرَأْهُ فِي كُلِّ شَهْرٍ قُلْتُ إِنِّي أَقْوَى عَلَى أَكْثَرَ مِنْ ذَلِكَ قَالَ فَاقْرَأْهُ فِي نِصْفِ كُلِّ شَهْرٍ قَالَ قُلْتُ إِنِّي أَقْوَى عَلَى أَكْثَرَ مِنْ ذَلِكَ قَالَ فَاقْرَأْهُ فِي كُلِّ سَبْعٍ لَا تَزِيدَنَّ وَبَلَغَنِي أَنَّكَ تَصُومُ الدَّهْرَ؟ قَالَ قُلْتُ إِنِّي لَأَصُومُهُ يَا رَسُولَ اللهِ قَالَ فَصُمْ مِنْ كُلِّ شَهْرٍ ثَلَاثَةَ أَيَّامٍ قَالَ قُلْتُ إِنِّي أَقْوَى عَلَى أَكْثَرَ مِنْ ذَلِكَ قَالَ فَصُمْ مِنْ كُلِّ جُمُعَةٍ يَوْمَيْنِ قَالَ قُلْتُ إِنِّي أَقْوَى عَلَى أَكْثَرَ مِنْ ذَلِكَ قَالَ فَصُمْصِيَامَ دَاوُدَ صُمْ يَوْمًا وَأَفْطِرْ يَوْمًا فَإِنَّهُ أَعْدَلُ الصِّيَامِ عِنْدَ اللهِ وَكَانَ لَا يُخْلِفُ إِذَا وَعَدَ وَلَا يَفِرُّ إِذَا لَاقَى