It was said, "Messenger of Allah, so-and-so never breaks his fast during the day, fasting continuously."He replied, "He has neither fasted nor broken his fast."
أخبرنا علي بن حجر قال أنبأنا إسمعيل عن الجريري عن يزيد بن عبد الله بن الشخير عن أخيه مطرف
قيل يا رسول الله إن فلانا لا يفطر نهارا الدهر قال لا صام ولا أفطر
Its isnad is sahih. Ahmad narrated it: 4/426, from Ismail bin Ulaya, with the same wording. It is also found in al-Kubra, no. 2682. Ibn Khuzayma graded it sahih: 3/311, no. 2151, as did Ibn Hibban, no. 937, and Hakim: 1/435, and Dhahabi.