All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
Allaah, The Exalted, preserved the religion of Islam from the loss of anything thereof. The Companions reported all that which the Muslim nation needs regarding their religion on the authority of their Prophet, sallallaahu ʻalayhi wa sallam. This does not negate the fact that they might have withheld some of what they heard form the Prophet, sallallaahu ʻalayhi wa sallam, that did not concern the Muslims competent for religious assignment and that is not related to the sharee'ah provisions and rulings. Abu Hurayrah said, “I have memorized two vessels of knowledge from the Messenger of Allaah, sallallaahu ʻalayhi wa sallam. I have imparted one of them to you, and if I were to disclose the other, this throat would be cut,” and he pointed to his throat. [Al-Bukhari]
Needless to assert that the knowledge that Abu Hurayrah withheld was not related to sharia provisions, nor was it pertaining to people’s needs. Al-Qastallaani said:
“By the first vessel, he was referring to the ahaadeeth that he memorized (which he imparted to people) and by the other the reports about fitnah (tribulations and political dissensions), the portents of the Last Hour, and what the Prophet, sallallaahu ʻalayhi wa sallam, informed him of what would occur of corruption in people’s religious commitment and worldly affairs by some young rulers from Quraysh. Abu Hurayrah said, 'If I wanted to tell you their names, I would do so.' Or he may have been referring to the ahaadeeth about the names, conditions and dispraise of these wicked rulers. Abu Hurayrah used to give hints about some of them, but he did not state anything openly for fear of being harmed at their hands, such as when he said, 'I seek refuge with Allaah from the beginning of the sixties (i.e. the sixtieth Hijri year), and the rule of youths (young men),' alluding to the caliphate of Yazeed ibn Muʻaawiyah, because it began in 60 AH. Allaah answered the supplication of Abu Hurayrah as he died a year before that.”
This clearly indicates the intended meaning that all that which we need of the Sunnah of the Prophet, sallallaahu ʻalayhi wa sallam, was reported to us. This does not deny the fact that much of what he, sallallaahu ʻalayhi wa sallam, had done or said and of which we have no need was not reported to us for one reason or another.
Allaah knows best.