Hadithcore
Sunan an-Nasa'i, 2378
sahih· Darussalam

'Abdullah bin 'Amr bin Al-As said:

"The Prophet (ﷺ) heard that I was fasting continually," and he quoted this Hadith. 'Ata said: "I am not sure how he put it, but I think he said: 'There is no fast for one who fats continually." 'Ata said: "someone who heard him told me that Ibn 'Umar (said) that the Prophet (ﷺ) said: 'Whoever fasts every day of his life, then he has not fasted."

أَخْبَرَنِي إِبْرَاهِيمُ بْنُ الْحَسَنِ، قَالَ حَدَّثَنَا حَجَّاجُ بْنُ مُحَمَّدٍ، قَالَ قَالَ ابْنُ جُرَيْجٍ سَمِعْتُ عَطَاءً، أَنَّ أَبَا الْعَبَّاسِ الشَّاعِرَ، أَخْبَرَهُ أَنَّهُ، سَمِعَ عَبْدَ اللَّهِ بْنَ عَمْرِو بْنِ الْعَاصِ، قَالَ بَلَغَ النَّبِيَّ صلى الله عليه وسلم أَنِّي أَصُومُ أَسْرُدُ الصَّوْمَ وَسَاقَ الْحَدِيثَ ‏.‏ قَالَ قَالَ عَطَاءٌ لاَ أَدْرِي كَيْفَ ذَكَرَ صِيَامَ الأَبَدِ لاَ صَامَ مَنْ صَامَ الأَبَدَ ‏.‏

References2 variants
In-Book Reference
Book 22, Hadith 289
English Reference
Vol. 3, Book 22, Hadith 2380