Ibn Majah

Commentary:
(1)
Abu Hurairah radi Allahu anhu accepted Islam in the 7th year of Hijrah. In this way, he had the opportunity to remain in the service of the Prophet sallallahu alayhi wa sallam and acquire knowledge for approximately four years. He passed away in 58 or 59 Hijri. Thus, he had the opportunity to spread knowledge during a period when many of the senior Companions had passed away or, due to being appointed to various administrative positions, did not have as much opportunity for teaching and preaching. In these circumstances, Abu Hurairah radi Allahu anhu made the teaching and dissemination of the Prophetic hadith his mission. Some people, in response to this, remarked that he narrates so many hadiths, whereas some other Companions who had the honor of a longer companionship with the Prophet sallallahu alayhi wa sallam do not narrate as many hadiths. In response, Abu Hurairah radi Allahu anhu clarified that his only objective is that, on the Day of Judgment, he should not be deemed guilty before Allah for concealing knowledge.

(2)
There are more hadiths narrated from Abu Hurairah radi Allahu anhu in the books of hadith than from any other Companion. In addition to the above-mentioned reasons, there are some other causes as well, such as:
(a)
The Muhajir Companions radi Allahu anhum would devote time to trade and similar activities so that, by earning lawful sustenance, they could fulfill the rights of their families. Similarly, most of the Ansari Companions were engaged in agriculture and had to spend considerable time in it, whereas Abu Hurairah radi Allahu anhu was among the Ashab al-Suffah, who, not paying attention to worldly livelihood, remained engaged in the acquisition of knowledge. For this reason, they often endured hunger as well.

(b)
Abu Hurairah radi Allahu anhu did not acquire knowledge only from the Prophet sallallahu alayhi wa sallam; rather, when the Prophet sallallahu alayhi wa sallam was at home or occupied with some other engagement, Abu Hurairah radi Allahu anhu would continue to learn hadiths and legal matters from other Companions radi Allahu anhum.

(c)
Abu Hurairah radi Allahu anhu had the special honor that the Prophet sallallahu alayhi wa sallam made a special supplication for him for the retention of knowledge. See: (Sahih al-Bukhari, Book of Knowledge, Chapter: Preservation of Knowledge, Hadith: 118; and Sahih Muslim, Virtues of the Companions, Chapter: Among the Virtues of Abu Hurairah al-Dawsi radi Allahu anhu, Hadith: 2492)

(3)
From the blessed verses mentioned in the narration, the reprehensibility of concealing knowledge and its severe punishment are understood. From this, it is known that concealing knowledge at the time of need is a major sin.