It was said to the Messenger of Allah ﷺ, "So-and-so never breaks his fast during the day throughout the year, eating only at night."The Messenger of Allah ﷺ replied, "He has neither fasted nor broken his fast."
أن رسول الله ﷺ قيل له: إن فلانا لا يفطر نهارا الدهر إلا ليلا، فقال رسول الله ﷺ: لا صام ولا أفطر.
Nasai (2379) and Imam Ahmad (19825) narrated it, and Ibn Khuzayma (2151) and Hakim (1/435) graded it sahih, all of them through various chains from Ismail bin Ulaya, from Jareeri, from Abu Ala, from Mutarrif, from Imran bin Husayn, who related the hadith.Ibn Hibban (3582) also narrated it through another route from Jareeri. Jareeri is Saeed bin Iyas, whose memory became confused toward the end of his life, but Ismail bin Ulaya was among those who heard from him before this confusion set in, and others corroborated him on this.Hakim said, "Sahih according to the criteria of the two Shaykhs."