Sahih Bukhari 1976

حَدَّثَنَا أَبُو الْيَمَانِ ، أَخْبَرَنَا شُعَيْبٌ ، عَنِ الزُّهْرِيِّ ، قَالَ : أَخْبَرَنِي سَعِيدُ بْنُ الْمُسَيِّبِ ، وَأَبُو سَلَمَةَ بْنُ عَبْدِ الرَّحْمَنِ ، أَنَّ عَبْدَ اللَّهِ بْنَ عَمْرٍو ، قَالَ : أُخْبِرَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، أَنِّي أَقُولُ : وَاللَّهِ لَأَصُومَنَّ النَّهَارَ ، وَلَأَقُومَنَّ اللَّيْلَ مَا عِشْتُ ، فَقُلْتُ لَهُ : قَدْ قُلْتُهُ بِأَبِي أَنْتَ وَأُمِّي ، قَالَ : فَإِنَّكَ لَا تَسْتَطِيعُ ذَلِكَ ، فَصُمْ وَأَفْطِرْ ، وَقُمْ وَنَمْ ، وَصُمْ مِنَ الشَّهْرِ ثَلَاثَةَ أَيَّامٍ ، فَإِنَّ الْحَسَنَةَ بِعَشْرِ أَمْثَالِهَا ، وَذَلِكَ مِثْلُ صِيَامِ الدَّهْرِ ، قُلْتُ : إِنِّي أُطِيقُ أَفْضَلَ مِنْ ذَلِكَ ، قَالَ : فَصُمْ يَوْمًا وَأَفْطِرْ يَوْمَيْنِ ، قُلْتُ : إِنِّي أُطِيقُ أَفْضَلَ مِنْ ذَلِكَ ، قَالَ : فَصُمْ يَوْمًا وَأَفْطِرْ يَوْمًا ، فَذَلِكَ صِيَامُ دَاوُدَ عَلَيْهِ السَّلَام وَهُوَ أَفْضَلُ الصِّيَامِ ، فَقُلْتُ : إِنِّي أُطِيقُ أَفْضَلَ مِنْ ذَلِكَ ، فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : لَا أَفْضَلَ مِنْ ذَلِكَ .

Narrated `Abdullah bin `Amr: Allah's Apostle was informed that I had taken an oath to fast daily and to pray (every night) all the night throughout my life (so Allah's Apostle came to me and asked whether it was correct): I replied, Let my parents be sacrificed for you! I said so. The Prophet said, You can not do that. So, fast for few days and give it up for few days, r ray and sleep. Fast three days a month as the reward of good deeds is multiplied ten times and that will be equal to one year of fasting. I replied, I can do better than that. The Prophet said to me, Fast one day and give up fasting for a day and that is the fasting of Prophet David and that is the best fasting. I said, I have the power to fast better (more) than that. The Prophet said, There is no better fasting than that.