Sunan Abi Dawud 2450
سنن أبي داود#2450Hasanحَدَّثَنَا أَبُو كَامِلٍ، حَدَّثَنَا أَبُو دَاوُدَ، حَدَّثَنَا شَيْبَانُ، عَنْ عَاصِمٍ، عَنْ زِرٍّ، عَنْ عَبْدِ اللَّهِ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَصُومُ - يَعْنِي مِنْ غُرَّةِ كُلِّ شَهْرٍ - ثَلاَثَةَ أَيَّامٍ .
Narrated Abdullah ibn Mas'ud: The Messenger of Allah (ﷺ) used to fast three days every month
Scholarly Authentication
The label above is the grade most of these scholars gave — 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. Each scholar's own wording:
Al-AlbaniHasan
Muhammad Muhyi Al-Din Abdul HamidHasan
Shuaib Al ArnautHasan
Zubair Ali ZaiIsnaad Hasan
In-book reference: 14:138