Hold fast to my sunnah

On the authority of Abu Najih al-Irbad ibn Sariya (may Allah be pleased with him), who said: “The Messenger of Allah (may Allah bless him and grant him peace) gave us an admonition that made hearts tremble and eyes overflow with tears. We said: ‘O Messenger of Allah, it is as though this were a farewell sermon; so counsel us.’ He said: "I counsel you to fear Allah, and to hear and obey even if a slave is set in authority over you. Those of you who live after me will see much disagreement. So hold fast to my Sunna and the sunna of the rightly guided caliphs; cling to it with your molar teeth. And beware of newly invented matters, for every innovation is misguidance."

Related by Abu Dawud and at-Tirmidhi, who said: “A hasan sahih hadith.”

[Abu Dawud 4607; at-Tirmidhi 2676]