"Fast one day, and you will have the reward of what is left." He said: "I am able to do more than that." He ﷺ said: "Fast two days, and you will have the reward of what is left." He said: "I am able to do more than that." He ﷺ said: "Fast three days and you will have the reward of what is left." He said: "I am able to do more than that." He ﷺ said: "Fast four days and you will have the reward of what is left." He said: "I am able to do more than that." He ﷺ said: "Observe the best kind of fasting before Allah, the fast of Dawud, peace be upon him; he used to fast one day and break his fast for one day." '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.'"  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لَهُ صُمْ يَوْمًا وَلَكَ أَجْرُ مَا بَقِيَ قَالَ إِنِّي أُطِيقُ أَكْثَرَ مِنَ ذَلِكَ قَالَ صُمْ يَوْمَيْنِ وَلَكَ أَجْرُ مَا بَقِيَ قَالَ إِنِّي أُطِيقُ أَكْثَرَ مِنْ ذَلِكَ قَالَ صُمْ ثَلاَثَةَ أَيَّامٍ وَلَكَ أَجْرُ مَا بَقِيَ قَالَ إِنِّي أُطِيقُ أَكْثَرَ مِنْ ذَلِكَ قَالَ صُمْ أَرْبَعَةَ أَيَّامٍ وَلَكَ أَجْرُ مَا بَقِيَ قَالَ إِنِّي أُطِيقُ أَكْثَرَ مِنْ ذَلِكَ قَالَ صُمْ أَفْضَلَ الصِّيَامِ عِنْدَ اللَّهِ صَوْمَ دَاوُدَ عَلَيْهِ السَّلاَمُ كَانَ يَصُومُ يَوْمًا وَيُفْطِرُ يَوْمًا  

'Amr said: "I spoke to the Prophet and he said: 'Fast one day out of ten and you will have the reward of the other nine.' I said: 'I am able to do more than that.' He said: 'Fast one day out of eight and you will have the reward of the other eight.' I said: 'I am able to do more than that.' He said: 'Fast one day out of eight and you will have the reward of the other seven.' I said: 'I am able to do more than that.' 'Fast one day and not the next."'  

ذَكَرْتُ لِلنَّبِيِّ ﷺ الصَّوْمَ فَقَالَ صُمْ مِنْ كُلِّ عَشْرَةِ أَيَّامٍ يَوْمًا وَلَكَ أَجْرُ تِلْكَ التِّسْعَةِ فَقُلْتُ إِنِّي أَقْوَى مِنْ ذَلِكَ قَالَ صُمْ مِنْ كُلِّ تِسْعَةِ أَيَّامٍ يَوْمًا وَلَكَ أَجْرُ تِلْكَ الثَّمَانِيَةِ قُلْتُ إِنِّي أَقْوَى مِنْ ذَلِكَ قَالَ فَصُمْ مِنْ كُلِّ ثَمَانِيَةِ أَيَّامٍ يَوْمًا وَلَكَ أَجْرُ تِلْكَ السَّبْعَةِ قُلْتُ إِنِّي أَقْوَى مِنْ ذَلِكَ قَالَ فَلَمْ يَزَلْ حَتَّى قَالَ صُمْ يَوْمًا وَأَفْطِرْ يَوْمًا  

"The Messenger of Allah said to me: 'Fast one day and you will have the reward of ten.' I said: 'Let me fast more.' He said: 'Fast two days and you will have the reward of nine.' I said: 'Let me fast more than that.' He said: 'Fast three days and you will have the reward of eight." (One of the narrators) Thabit said: "I mentioned that to Mutarrif and he said: 'I only see that he is making more effort for less reward.'"  

لِي رَسُولُ اللَّهِ ﷺ صُمْ يَوْمًا وَلَكَ أَجْرُ عَشْرَةٍ فَقُلْتُ زِدْنِي فَقَالَ صُمْ يَوْمَيْنِ وَلَكَ أَجْرُ تِسْعَةٍ قُلْتُ زِدْنِي قَالَ صُمْ ثَلاَثَةَ أَيَّامٍ وَلَكَ أَجْرُ ثَمَانِيَةٍ قَالَ ثَابِتٌ فَذَكَرْتُ ذَلِكَ لِمُطَرِّفٍ فَقَالَ مَا أُرَاهُ إِلاَّ يَزْدَادُ فِي الْعَمَلِ وَيَنْقُصُ مِنَ الأَجْرِ وَاللَّفْظُ لِمُحَمَّدٍ