Sunan an-Nasa'i 2382
سنن النسائي#2382SahihIt was narrated that 'Umar said:"We were with the Messenger of Allah and we passed by a man. They said: 'O Prophet of Allah, this man has not broken his fast for such and such a time.' He said: 'He has neither fasted nor broken his fast."' '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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih Lighairihi
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 22:293