Sunan an-Nasa'i, Hadith 2379 ⓘ
It was narrated that 'Imran said: "It was said: 'O Messenger of Allah, so and so never broke his fast, even for one day for the rest of his life.' 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."
أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ أَنْبَأَنَا إِسْمَاعِيلُ، عَنِ الْجُرَيْرِيِّ، عَنْ يَزِيدَ بْنِ عَبْدِ اللَّهِ بْنِ الشِّخِّيرِ، عَنْ أَخِيهِ، مُطَرِّفٍ عَنْ عِمْرَانَ، قَالَ قِيلَ يَا رَسُولَ اللَّهِ إِنَّ فُلاَنًا لاَ يُفْطِرُ نَهَارًا الدَّهْرَ . قَالَ " لاَ صَامَ وَلاَ أَفْطَرَ " .
also referenced under: Book 22, Hadith 290 (In-Book) & Volume 3, Book 22, Hadith 2381 (DarusSalam)