The Forty Hadiths of Al-Nawawi.
On the authority of Abu Najih Al-Irbad ibn Sariya (may Allah be pleased with him), who said:
"The Messenger of Allah (peace and blessings of Allah be upon him) delivered a sermon to us that filled our hearts with fear and caused our eyes to shed tears.
So we said: 'O Messenger of Allah, it is as though this were a farewell sermon,
so advise us.'
He said:
'I advise you to fear Allah, and to listen and obey,
even if an Abyssinian slave were appointed as a ruler over you.
For indeed, whoever among you lives long
will see much disagreement.
So adhere to my Sunnah and the Sunnah of the Rightly Guided Caliphs;
bite onto it with your molar teeth.
And beware of newly invented matters,
for every innovation is a misguidance.'"
It was narrated by Abu Dawud and Al-Tirmidhi,
and he said: It is a good and authentic hadith.
This hadith
teaches us that a sincere sermon moves the heart,
awakening it and bringing it closer to Allah.
It also shows the Prophet (peace be upon him) advising us to adhere to his Sunnah
and the Sunnah of the Rightly Guided Caliphs,
and to stay away from innovations and division after his time.
Thus, salvation lies in adhering firmly to the Book and the Sunnah
and remaining steadfast upon the truth,
no matter how great the tribulations become.