Sunan an-Nasa'i 2373
سنن النسائي#2373Sahihأَخْبَرَنِي حَاجِبُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا الْحَارِثُ بْنُ عَطِيَّةَ، قَالَ حَدَّثَنَا الأَوْزَاعِيُّ، عَنْ عَطَاءِ بْنِ أَبِي رَبَاحٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ صَامَ الأَبَدَ فَلاَ صَامَ " .
It was narrated that 'Abdullah bin 'Umar said:"The Messenger of Allah said: 'Whoever fasts every day of his life, then he has not fasted
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:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 22:284