Hold fast to the Sunnah

On the authority of Abū Najīḥ al-ʿIrbāḍ ibn Sāriya, may Allah be pleased with him, who said: The Messenger of Allah ﷺ gave us an admonition by which hearts trembled and eyes shed tears, so we said: O Messenger of Allah, it is as if this is a farewell admonition, so advise us. He said: I advise you to fear Allah, and to hear and obey even if a slave is put in command over you. Whoever of you lives will see much disagreement, so you must hold to my Sunnah and the Sunnah of the rightly guided caliphs; bite onto it with your molar teeth. Beware of newly invented matters, for every innovation is misguidance.