The explanation of Abu Hurayrah's (may Allah be pleased with him) memorization of the Sunnah and his diligence in it, and the refutation of those who criticized Abu Hurayrah and his narration.

The Shaykh : Before this, I recalled something in the previous hadith where Khubayb, when mentioning the story, cited Abu Hurayrah as saying: "I heard the Messenger of Allah (peace and blessings be upon him) say this hadith." I want to remind, especially those of our brothers present who are keen on reading the Sunnah and reading what they may read in some magazines that gather whatever comes and goes of knowledge, whether authentic or not.
...There is much criticism of the memorizer of the Sunnah, Abu Hurayrah (may Allah be pleased with him). For example, they say from among these doubts: Abu Hurayrah only reached the end of Islam; he embraced Islam in the Battle of Khaybar, so he only experienced about two and a half years of the life of the Messenger (peace be upon him). How, then, is he the most memorizing of the Companions and the one with the most hadith? The answer to this from the people of hadith can be summarized in two answers or two reasons:
The first reason: His diligence in staying close to the Messenger (peace be upon him) and accompanying him in all circumstances. He was not married and did not own livestock or crops, and he was content with the least of sustenance. In fact, he would starve himself for hours, even days, to keep close to the Messenger (peace be upon him) and benefit from him. It was as if he felt that his Islam was late, so he wanted to compensate for the much good he missed when he did not embrace Islam from the beginning of the Messenger's (peace and blessings be upon him) mission. Therefore, he devoted himself to this Prophetic knowledge to acquire it from him (peace be upon him). This is the first reason, and it is mentioned in some hadiths. 'Umar ibn al-Khattab acknowledged Abu Hurayrah's superiority and said: "The bustle of the markets occupied us from knowledge." 'Umar himself, the second Rightly Guided Caliph, said this, whereas nothing occupied Abu Hurayrah. This attention of his to the company of the Messenger (peace be upon him) and receiving hadith from him made him have more material in hadith than the other Companions, even those who were among the earliest in Islam.
The second reason: It is a fundamental reason, but this hadith relates to the first type. Because he said that Abu Hurayrah says: "I heard the Messenger of Allah (peace and blessings be upon him)." So this hadith was heard by him directly, and Ibn 'Umar benefited from him as you heard in the story. As for the second answer, it is that Abu Hurayrah also connected with the Companions who preceded him in Islam and took from them what they had heard from him (peace be upon him), either due to their precedence, or due to their seclusion and private gatherings with the Prophet (peace and blessings be upon him). He added this to what he received directly from the Prophet (peace and blessings be upon him), so the result was that he was the most memorizing of all the Companions of the Messenger (peace be upon him) without exception. Abu Hurayrah thought something that scientific research has shown to be a misconception on his part, which was to his benefit; that is, it was a misconception and it was to his benefit. He used to say about one of the Companions, 'Abdullah ibn 'Amr ibn al-'As, not 'Abdullah ibn 'Umar ibn al-Khattab, that he was more memorizing than him, and he justified this by saying: "He used to write and I did not write." So he assumed a premise that might be correct, but research and induction showed that Abu Hurayrah remained the most memorizing of the Companions, more than any individual among them, including this 'Abdullah whom Abu Hurayrah thought was more memorizing than him. The reason is what we mentioned earlier: his exclusive devotion to the Prophet (peace and blessings be upon him) by his diligence in receiving hadith from him, then his connection with the Companions and gathering what they had of the Sunnah, so he had more hadith than 'Abdullah ibn 'Amr ibn al-'As.
It is very easy to discover this. We take "Musnad Imam Ahmad," which is still the broadest of the books of the Sunnah in collecting material of hadith traced to the Messenger (peace be upon him) in six large volumes. The second volume contains the Musnad of this 'Abdullah ibn 'Umar, the Musnad of that 'Abdullah ibn 'Amr ibn al-'As, the Musnad of another Companion who is not well known by his kunya, Abu Rumthah, and the Musnad of Abu Hurayrah. If we take the Musnad of Abu Hurayrah, it takes up half of this entire volume, just the Musnad of Abu Hurayrah alone, and the first half is taken by these Companions: Ibn 'Umar, Ibn 'Amr, or Abu Rumthah. So the hadith of Abu Hurayrah is abundant in number, and where is the hadith of Ibn 'Amr in comparison to his? May Allah be pleased with him for his diligence in knowledge, he preserved for us from the Sunnah what no other Companion preserved. Many hadiths come from other routes, like this hadith we are currently discussing. A hadith of Thawban will come to you now, and in the hadith of Abu Hurayrah you learned that the Lady A'ishah confirmed Abu Hurayrah in his hadith. But sometimes hadiths come to him that he narrates alone and no one from the Companions supports him in that; for example, the famous hadith in "Sahih Muslim": Allah (Blessed and Exalted is He) said: . This is a long hadith and a holy hadith, narrated in "Musnad" as well as in "Sahih Muslim." Abu Hurayrah narrated it alone without any of the other Companions. And how many such virtues does he have, where the credit for preserving them from the Prophet (peace and blessings be upon him) returns to him.