Sunan an-Nasa'i, Hadith 2375 ⓘ
'Ata said: "someone who heard him told me that Ibn 'Umar (said) that the Prophet said: 'Whoever fasts every day of his life, then he has not fasted."
أَخْبَرَنَا الْعَبَّاسُ بْنُ الْوَلِيدِ، قَالَ حَدَّثَنَا أَبِي وَعُقْبَةُ، عَنِ الأَوْزَاعِيِّ، قَالَ حَدَّثَنِي عَطَاءٌ، قَالَ حَدَّثَنِي مَنْ، سَمِعَ ابْنَ عُمَرَ، يَقُولُ قَالَ النَّبِيُّ صلى الله عليه وسلم " مَنْ صَامَ الأَبَدَ فَلاَ صَامَ " .
also referenced under: Book 22, Hadith 286 (In-Book) & Volume 3, Book 22, Hadith 2377 (DarusSalam)