Abu Hurairah was on a journey, and when the group stopped to rest, they sent for him while he was praying so that he might eat with them. He told the messenger, "I am fasting." When the food was set out and they were nearly finished eating, he came and began to eat.The people looked at their messenger, who said, "Why are you looking at me? He told me himself that he was fasting."Abu Hurairah said, "He spoke the truth. I heard the Messenger of Allah ﷺ say, 'Fasting the month of patience and three days of every month is equivalent to fasting the entire year.' I have already fasted three days of this month, so I am breaking my fast by Allah's allowance of ease, while still being counted as fasting through Allah's multiplication of reward."
أنه كان في سفر، فلما نزلوا أرسلوا إليه وهو يصلي ليطعمهم، فقال للرسول: إني صائم. فلما وضع الطعام، وكادوا يفرغون جاء فجعل يأكل. فنظر القوم إلى رسولهم، فقال: ما تنظرون؟ قد أخبرني أنه صائم. فقال أبو هريرة: صدق، إني سمعت رسول الله ﷺ يقول: صوم شهر الصبر، وثلاثة أيام من كل شهر صوم الدهر. فقد صمت ثلاثة أيام من كل شهر، وأنا مفطر في تخفيف الله، وصائم في تضعيف الله.
Narrated by Nasai (2408), Ahmad (7577, 8986, 10663), and Ibn Hibban graded it sahih (3659), and Bayhaqi (4/293), all of them through various routes from Hammad bin Salama, from Thabit, from Abu Uthman Nahdi, from Abu Hurairah, and he mentioned it, except that some of them did not mention the story. Its isnad is sahih, but Daraqutni said in al-Ilal (2856), "The hadith of Abu Dharr is closer to being correct," and this is what follows.As for his statement that the hadith of Abu Dharr is closer to being correct, he means in comparison to this isnad which he presented through the route of Hammad bin Salama with his chain. Otherwise, the original hadith of Abu Hurairah is found in the Sahihayn through a different isnad, and it is more sahih than the hadith of Abu Dharr. However, I was not able to locate this statement in al-Ilal, so did Daraqutni overlook it? Tirmidhi has pointed to it following the hadith of Abu Dharr, as will follow.