Abbad bin Kathir came to Madinah and went over to the gathering of Ala. He took him by the hand, made him stand up, and said, "O Allah, this man narrates from his father, from Abu Hurairah, that the Messenger of Allah ﷺ said, 'When Shaban is halfway through, do not fast.'"Ala replied, "O Allah, my father did indeed narrate this to me from Abu Hurairah, from the Prophet ﷺ."
قدم عباد بن كثير المدينة، فمال إلى مجلس العلاء، فأخذ بيده فأقامه ثم قال: اللهم إن هذا يحدث عن أبيه، عن أبي هريرة، أن رسول الله ﷺ قال: إذا انتصف شعبان فلا تصوموا. فقال العلاء: اللهم إن أبي حدثني عن أبي هريرة، عن النبي ﷺ بذلك.
Abu Dawud (2337), Tirmidhi (738), and Ibn Majah (1651) all narrated it from the hadith of Abdul-Aziz bin Muhammad with his chain of transmission. The wording given is that of Abu Dawud, and Tirmidhi and Ibn Majah did not mention the story. Ibn Hibban graded it sahih (3589, 3591), and he narrated it through another route from Ala in a shortened form. Imam Ahmad reported it (9707) through another route from Ala bin Abdul-Rahman bin Yaqub with his chain of transmission, and in it, "When it is the middle of Shaban, refrain from fasting until Ramadan comes."Abu Dawud said, Abdul-Rahman used not to narrate it. I said to Ahmad, why? He said, because he held the view that the Prophet ﷺ used to join Shaban to Ramadan, yet here he reported from the Prophet ﷺ the opposite of that. Abu Dawud said, "In my view this is not the opposite of that, and no one other than Ala reported it from his father." Tirmidhi said, the hadith of Abu Hurairah is hasan sahih, and we know it only through this route with this wording.The meaning of this hadith, according to some scholars, is that a man who has been breaking his fast, when only a little of Shaban remains, should begin fasting in preparation for the month of Ramadan. It has been reported from Abu Hurairah, from the Prophet ﷺ, something resembling their view, where he said, "Do not bring forward the month of Ramadan with fasting, unless it coincides with a fast one of you was already observing." This hadith indicates that the disapproval applies only to one who deliberately fasts in preparation for Ramadan.Scholars have several approaches to reconciling the hadith of Ayesha with the hadith of Abu Hurairah, some of which I have mentioned in Minna Kubra (3/430).As for Bayhaqi's statement (4/209) that Abu Dawud narrated it from Qutayba, and then Abu Dawud said that Ahmad bin Hanbal said, "This is a munkar hadith," and said that Abdul-Rahman used not to narrate it, I did not find this statement in the printed edition of Abu Dawud's work from the transmission of Ibn Dasa, nor did I find it in the book Masail Abi Dawud of Imam Ahmad, so take note.Hafiz bin Qayyim said in Tahzib Sunan (3/223–224) that this hadith does not contradict the other hadith as Abdul-Rahman bin Mahdi supposed, and the fact that Ala was not corroborated in it is not a discrediting flaw according to the hadith scholars. Rather, it is a sahih hadith meeting the standard of Muslim, for Muslim reported in his Sahih several hadiths from Ala, from his father, from Abu Hurairah, and his being the sole transmitter of it is the sole transmission of a trustworthy narrator reporting an independent hadith, and there are several parallels to this in the Sahih. He then spoke at length in establishing it as sahih.