The Prophet ﷺ said to me, "You fast daily all the year and pray every night all the night?" I replied in the affirmative. The Prophet ﷺ said, "If you keep on doing this, your eyes will become weak and your body will get tired. He who fasts all the year is as he who did not fast at all. The fasting of three days (a month) will be equal to the fasting of the whole year." I replied, "I have the power for more than this." The Prophet ﷺ said, "Then fast like the fasting of David who used to fast on alternate days and would never flee from the battle field, on meeting the enemy."  

سَمِعْتُ أَبَا الْعَبَّاسِ الْمَكِّيَّ وَكَانَ شَاعِرًا وَكَانَ لاَ يُتَّهَمُ فِي حَدِيثِهِ قَالَ سَمِعْتُ عَبْدَ اللَّهِ بْنَ عَمْرِو بْنِ الْعَاصِ ؓ قَالَ قَالَ لِي النَّبِيُّ ﷺ إِنَّكَ لَتَصُومُ الدَّهْرَ وَتَقُومُ اللَّيْلَ فَقُلْتُ نَعَمْ قَالَ إِنَّكَ إِذَا فَعَلْتَ ذَلِكَ هَجَمَتْ لَهُ الْعَيْنُ وَنَفِهَتْ لَهُ النَّفْسُ لاَ صَامَ مَنْ صَامَ الدَّهْرَ صَوْمُ ثَلاَثَةِ أَيَّامٍ صَوْمُ الدَّهْرِ كُلِّهِ قُلْتُ فَإِنِّي أُطِيقُ أَكْثَرَ مِنْ ذَلِكَ قَالَ فَصُمْ صَوْمَ دَاوُدَ عَلَيْهِ السَّلاَمُ كَانَ يَصُومُ يَوْمًا وَيُفْطِرُ يَوْمًا وَلاَ يَفِرُّ إِذَا لاَقَى  

Messenger of Allah ﷺ was informed about my fasts, and he came to me and I spread for him a leather cushion stuffed with palm fires, but he sat on the ground and the cushion remained between me and him, and then he said, "Isn't it sufficient for you to fast three days a month?" I replied, "O Allah's Apostle! (I can fast more)." He said, "Five?" I replied, "O Messenger of Allah ﷺ! (I can fast more)." He said, "Seven?" I replied, "O Messenger of Allah ﷺ! (I can fast more)." He said, "Nine (days per month)?" I replied, "O Messenger of Allah ﷺ! (I can fast more)" He said, "Eleven (days per month)?" And then the Prophet said, "There is no fast superior to that of the Prophet ﷺ David it was for half of the year. So, fast on alternate days."  

فَحَدَّثَنَا أَنَّ رَسُولَ اللَّهِ ﷺ ذُكِرَ لَهُ صَوْمِي فَدَخَلَ عَلَىَّ فَأَلْقَيْتُ لَهُ وِسَادَةً مِنْ أَدَمٍ حَشْوُهَا لِيفٌ فَجَلَسَ عَلَى الأَرْضِ وَصَارَتِ الْوِسَادَةُ بَيْنِي وَبَيْنَهُ فَقَالَ أَمَا يَكْفِيكَ مِنْ كُلِّ شَهْرٍ ثَلاَثَةُ أَيَّامٍ قَالَ قُلْتُ يَا رَسُولَ اللَّهِ قَالَ خَمْسًا قُلْتُ يَا رَسُولَ اللَّهِ قَالَ سَبْعًا قُلْتُ يَا رَسُولَ اللَّهِ قَالَ تِسْعًا قُلْتُ يَا رَسُولَ اللَّهِ قَالَ إِحْدَى عَشْرَةَ ثُمَّ قَالَ النَّبِيُّ ﷺ لاَ صَوْمَ فَوْقَ صَوْمِ دَاوُدَ عَلَيْهِ السَّلاَمُ شَطْرَ الدَّهْرِ صُمْ يَوْمًا وَأَفْطِرْ يَوْمًا