Jami` at-Tirmidhi 770
جامع الترمذي#770Sahihحَدَّثَنَا هَنَّادٌ، حَدَّثَنَا وَكِيعٌ، عَنْ مِسْعَرٍ، وَسُفْيَانَ، عَنْ حَبِيبِ بْنِ أَبِي ثَابِتٍ، عَنْ أَبِي الْعَبَّاسِ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَفْضَلُ الصَّوْمِ صَوْمُ أَخِي دَاوُدَ كَانَ يَصُومُ يَوْمًا وَيُفْطِرُ يَوْمًا وَلاَ يَفِرُّ إِذَا لاَقَى " . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ . وَأَبُو الْعَبَّاسِ هُوَ الشَّاعِرُ الْمَكِّيُّ الأَعْمَى وَاسْمُهُ السَّائِبُ بْنُ فَرُّوخَ . قَالَ بَعْضُ أَهْلِ الْعِلْمِ أَفْضَلُ الصِّيَامِ أَنْ تَصُومَ يَوْمًا وَتُفْطِرَ يَوْمًا . وَيُقَالُ هَذَا هُوَ أَشَدُّ الصِّيَامِ .
Abdullah bin Amr narrated that:The Messenger of Allah said: "The most virtuous fast is the fast of my brother Dawud. He would fast a day, and not fast (the next) day. He would not flee at the time of engagement (with the enemy)
Scholarly Authentication
The label above is the grade most of these scholars gave, each scholar counted once — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. When they judged only its chain of narrators (“Isnaad”), the label says “Sound chain”. Each scholar's own wording:
Our source also lists this ruling under Ahmad Muhammad Shakir, the editor of the printed edition it was taken from. It is al-Albani's ruling printed again, so it is counted once.
In-book reference: 8:89