حَدَّثَنَا أَحْمَدُ بْنُ عَبْدَةَ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، حَدَّثَنَا غَيْلاَنُ بْنُ جَرِيرٍ، عَنْ عَبْدِ اللَّهِ بْنِ مَعْبَدٍ الزِّمَّانِيِّ، عَنْ أَبِي قَتَادَةَ، قَالَ: قَالَ عُمَرُ بْنُ الْخَطَّابِ: يَا رَسُولَ اللَّهِ! كَيْفَ بِمَنْ يَصُومُ يَوْمَيْنِ وَيُفْطِرُ يَوْمًا؟ قَالَ: ‏"‏ وَيُطِيقُ ذَلِكَ أَحَدٌ ‏"‏ ‏.‏ قَالَ: يَا رَسُولَ اللَّهِ! كَيْفَ بِمَنْ يَصُومُ يَوْمًا وَيُفْطِرُ يَوْمًا؟ قَالَ: ‏"‏ ذَلِكَ صَوْمُ دَاوُدَ ‏"‏ ‏.‏ قَالَ: كَيْفَ بِمَنْ يَصُومُ يَوْمًا وَيُفْطِرُ يَوْمَيْنِ؟ قَالَ: ‏"‏ وَدِدْتُ أَنِّي طُوِّقْتُ ذَلِكَ ‏"‏ ‏.‏

It wasnarrated that Abu Qatadah said

“Umar bin Khattab said: ‘OMessenger of Allah! What about a person who fasts two days and doesnot fast one day?’ He said: ‘Is anyone able to do that?’ Hesaid: ‘OMessenger of Allah! What about a person who fasts one dayand not thenext?’ He said: ‘That is the fast of Dawud.’ Hesaid: ‘What about aman who fasts one day and does not fast thenext two days?’ He said:‘I wish that I were given the ability todo that.’”